Wired's How-To Wiki takes a look at the most common suggestions for speeding up your Mac OS X desktop and picks out a few that really can help scale back memory use—and also highlights the perennial suggestions that don't do a thing and waste your time. For example: Cleaning up an icon-laden desktop = small but real memory savings. Repairing file permissions = Not at all necessary. Hit the link below for more tips and a chance to throw your own $.02 in. For another angle on system speed, try software tuneups to speed up your Mac.