Originally Posted by
Rico_SPD
Mine doesn't look like either (stock Huffy MTB). The cranks are curved coming out of the bike. There's a hex nut around the base where the crank (non-drive side) comes out. Would an adjustable wrench or channel-lock pliers work?
Neither crank is loose, but if you hold onto both pedals with your hands, you can 'wobble' them side to side.
To be clear, it sounds like you have a one-piece ("Ashtabula") bottom-bracket/crank. Does yours look like the right-most picture?
http://sheldonbrown.com/gloss_bo-z.html#bottom
Edit: Rico_SPD, just noticed you are not the OP. If you have a one-piece system, the replies in this thread won't really help you. Check out:
http://sheldonbrown.com/opc.html