If you don't know what BLD is, ignore this page. This is not a step in a normal speedsolve, but rather a completely different method by which a person solve a Rubik's cube blindfolded.
"Oooh!! That sounds interesting! Can I do it?"
Maybe, but I'm not going to babysit you along the way. Sorry to sound harsh, but learning to blindsolve takes many days of hard work and concentration. I won't answer questions about blindsolving. There are main three methods. The 3Cycle or 3OP Method (3 pieces at a time, more stages), The Pochmann Method (2 pieces at a time, less stages), and Freestyle (which can't really be taught, it just comes with the ability to visualize the cube and improvise moves). Which method is fastest? Freestyle; but good luck learning it. The other two both have ups and downs. I'll be teaching 3Cycle in my tutorial, and therefore the following algorithms are most useful for 3Cycle solves.
I'm not going to have an entire tutorial yet, but I will put up the algorithms that I use for this. If you're interested in learning, check out this link: http://www.cubefreak.net/BLD/3OP_guide.htm
The 3Cycle method is a method which separates orientation and permutation into two separate steps. This way, permutation is a lot simpler than in the other methods because since the pieces are preoriented, we only have to worry about where the pieces themselves go, and not which direction the stickers need to face. Pochmann solvers will argue that 3OP is slower because it requires two separate steps to orient and then permute pieces, but I believe that 3Cycle more than makes up for this during the permutation step, when we are permuting 3 pieces at once rather than 2.
The following four sections (Eo, Co, Cp, Ep) are the steps of a 3Cycle blindsolve, in the order that I do them. Please do not view this page as a tutorial! This is more useful to people who know the 3Cycle method, and are looking for some extra 'shortcut' algorithms.
2 EdgeFlip: (M' U M' U M' U2) (M U M U M U2) Changes orientation of 'front' and 'back' top layer edges with no side effects.
4 EdgeFlip: (M' U M' U M' U M' U) (M U M U M U M U) Changes orientation of all top layer edges with no sideeffects.  *Assume for my images that green is in the front, and orange is on the right. Edge orientation is by far the easiest step. If you're a beginner, you should practice this step a lot because it will give you some experience with blind set up moves. When I was just learning to blindsolve, I used to try to blindsolve just the orientation. I recommend doing this, so that you will become very strong in edge and corner orientation. This will help you later on when you're trying to nail permutation. So basically, it works like this. Decide how many pieces you want to orient at once: 2 or 4. The less you do at once, the easier the setup move is. Suppose you want to play it safe and do 2 pieces. All you have to do is find a way, any way at all, to bring those 2 pieces into the topfront and topback spots of the cube so you can use the 2 edgeflip algorithm to fix them. Then, just undo the set up move to return everything to normal. If you did it right, you should have changed only the orientation of your 2 pieces, and the rest of the cube will be entirely unaffected (notice how the descriptions of these algorithms say "with no sideeffects"). As you get better with setup moves, you can try 4 pieces at a time. There are also other algorithms available for this step, but since the 4 edgeflip is so efficient they are not really needed until you are comfortable with a sort of blind speedsolving. 
Corner Orientation Commutators:
(D' R' D R)(D' R' D R)
Twists Corner "2" clockwise with side effects in bottom two layers. Commutator; On a cycle of three. Inverse of commutator below.
(R' D' R D)(R' D' R D) Twists Corner "2" counterclockwise with side effects in bottom two layers. Commutator; On a cycle of three. Inverse of commutator above.
Corner orientation is confusing to learn. Basically, you just have to learn how the commutator works. For these commutators I prefer Us and Rs. I actually tilt the cube to the left (z') and remember that the one that starts with R' U' is clockwise, and the one that starts with U' R' is anticlockwise. This seems to be the most comfortable way to do the commutators.
Do not learn the Algorithms until you are very, very comfortable and consistent with blindsolving. They are not necessary, but they do serve as nice shortcuts in this step. The reason that the algorithms are much longer than the normal OLLs is that the normal OLL algorithms have permutation sideeffects which must me taken into account during a blindsolve. You don't need to know these, but they help a lot once you start getting faster because they can fix lots of corners at once, instead of one at a time with the commutator. These are a lot less versitile than the commutator though, so don't even think of learning these until you are quite comfortable with BLD. Note, these can be used on any face of the cube if you use a cube rotation.  Corner Orientation Algorithms (Advanced): Make sure you know all the stuff in the left column first!
"Safe" Sune 01: (R U R' U R U2 R') U2 U (R U' R U R U R U' R' U' R2) U' i.e. (Sune 01) U' (Ub Permutation) U' Twists corners "2", "3", and "4" all in a clockwise direction. Ub Permutation corrects the side effects produced by using Sune 01.
"Safe" Sune 02: (R' U' R U' R' U2 R) U2 U (R2 U R U R' U' R' U' R' U R') U' i.e. (Sune 02) U' (Ua Permutation) U' Twists corners "1", "2", and "3" all in an anticlockwise direction. Ua Permutation corrects the side effects produced by Sune 02.
"Safe" Sune 03: (R U2 R' U' R U R' U' R U' R') U2 (R2 U R U R' U' R' U' R' U R) U2 i.e. (Sune 03) U2 (Ua Permutation) U2 Fixes two sets of headlights as seen in picture. Ua Permutation corrects the side effects produced by Sune 03.
"Safe" Sune 04: (R U2 R2 U' R2 U' R2 U2 R) (R U' R U R U R U' R' U' R2) U2 i.e. (Sune 04) (Ub Permutation) U2 Fixes two pairs as seen in picture. Ub Permutation corrects the side effects produced by Sune 04 
l' U R' D2 R U' R' D2 R2 x' Swaps corners "2", "3", "4" in a clockwise direction with no side effects. This is Aa Permutation.
x R2 D2 R U R' D2 R U' R x' Swaps corners "2", "3", and "4" in a counterclockwise direction with no side effects. This is Ab Permutation.
Setup Moves: For Corner Permutation, there are restrictions on the setup moves. Do not use any setup move that change the orientation of corners. i.e. Use quarter turns on only the U and D layers, for all other layers you must only use double turns (R2, F2, L2, B2) to preserve the orientation. For algorithms you only need to know the first two (Aa and Ab Permutation), but it's nice to know at least one of the others as well. This prevents a very difficult setup move. 
R2 D R2 D' R2 U2 R2 D R2 D' R2 U2 Swaps corners "1", "3", "7" in a counterclockwise direction with no side effects. This algorithm is not necessary, but can help you to avoid a very difficult setup move.
[R2 D R2 D' R2 U2 R2 D R2 D' R2 U2]*2 Swaps corners "1", "3", "7" in a counterclockwise direction with no side effets. Again, not necessary, but helpful. I just use the ccw version twice.
Double Transposition: (l U' R' U) (R U' R' U) (R U' R' U) x Swaps corners "2" & "3" with corners "4" & "7", respectively. Sometimes I call this the elevator algorithm, as it has the ability to lift corner 7 to the 2 position with easy to handle side effects. 
Ua Permutation: R2 U R U R' U' R' U' R' U R' Cycles edges "a", "b", and "d" in a clockwise direction.
Ub Permutation: R U' R U R U R U' R' U' R2 Cycles edges "a", "b", and "d" in a counterclockwise direction
Setup Moves: For Edge permutation there are also restrictions on setup moves. Do not use any setup moves that change the orientation of edge pieces. i.e. Quarter turns on the R and L face are off limits, but double turns are fine. There are no restrictions on the other (U, F, D, B) faces.  Another Useful Case to Know: M' U2 M U2 Cycles hilighted edges in an R' direction. or U2 M' U2 M Cycles hilighted edges in an R direction.
