moxfyre

I use fine steel wool, personally. It removes rust better than sandpaper, but removes solid metal WORSE than sandpaper... so you clean the rust off a frame without taking much of the good solid metal underneath.

By the way, wheels shouldn't be rusting... unless you have very low-quality non-stainless spokes or steel rims. Steel rims are obsolete because they're heavy and have VERY poor braking traction in rain, so it's a good idea to replace them if possible.