you can gain extra height and distance with this move, you basically take out a bomb, throw it up on yoru double jump, then spin attack up INTO the bomb itself detonating it and making you able to do the special move again.

Quote Originally Posted by Smash Boards
Bomb Jumping: Samus can actually jump using her Bombs to propel her. She cannot stay in the air indefinitely, but it is very useful as a recovery. Basically, after being knocked off the stage, lay a bomb, fall a little, lay another bomb(causing you to stall long enough for the first bomb to explode), then push the control stick in the direction you wish to go (DI), then repeat the process. Samus can also grapple the stage when she gets close enough. Link also has the ability to bomb jump, but it is not quite as effective and much more difficult to pull off. Basically once you’re off the edge (from being hit), pull a bomb out, throw it, and proceed to jump and up B, if you do it correctly then the bomb will blow up on you and you will be able to perform another up B move.
You can go from the center stage of oldschool Yoshi's Island to the FAR edge cloud using Link's bomb jump. You can also seemingly go up alot higher than previously thought of and out of sticky situations especially with good hookshot control(which i am working on ><).

As for Tiers this is the only tier list that i feel is accurate and up to date:

Quote Originally Posted by Smash Boards
Tier List

Intro: Alot of people ask about the tier list, so here it is. Just for a note though, do not make topics regarding the tier list, they will (99% of the time) be closed (For new people especially, PM me if you have any questions). Trust me, if you have a problem with this list (say the Ice Climbers placement), it is already known. If you think tiers in general are false, go to gamefaqs, cause that arguement will get closed here for sure. Ohh, and the link to the topic from March 19th, 2005:
Tier Topic

Top Tier
Sheik
Fox
Marth

Upper Tier
Peach
Falco
C. Falcon
Samus

High Tier
Jigglypuff
Dr. Mario
Ganondorf
Mario
Ice Climbers

Middle Tier
Luigi
Link
Roy
DK
Pikachu
Zelda

Lower Tier
Ness
Young Link
Yoshi
Kirby
Mr. Game & Watch
Bowser

Bottom Tier
Mewtwo
Pichu