I could probably use one too, my Windows is dying and I can't be bothered to do a format and fresh install (too many unorganized shit on drive C to go through and backup)... Never used a reg clear on XP before, I remember using one on Win 98 though.
Seconding votes for Easy Cleaner and jv16 PowerTools. I've been using both for awhile (Easy Cleaner since Win 98) and together they both offer pretty much anything you need and are both fairly friendly (Easy Cleaner recently made a huge jump forward in terms of UI).