golf-a-holic gave great advice.
Also, Golfsmith sells shaft extenders for $1.95 each. One can be used for two clubs, as they are about 8" in length, with each end tapered. You need to specifiy if the butt end of the club is .580 or .600. Use epoxy to set the end into the club, let it cure, and cut to the desired length using a tube cutter or hacksaw. Install a new grip and you're done. It really is pretty simple.
I just extended a sand wedge 1" to match my other clubs, and I can feel the difference.
Good luck - its kinda fun to do this stuff ourselves.
