I saw today that Staples has McAfee AntiSpyware free after rebate, so I picked up a copy. I re-did my home machine when XP SP2 was released, so it's pretty clean. After installing and updating McAfee's product, I did a scan, and it detected 3 things: "Adult Links": This was something related to the ICQ search bar that ICQ annoyingly installed in IE, but since I don't use IE, I really hand't worried about removing it yet.
"ABCKeylogger" mouse/keystroke logger: This is what it thinks my registry entry for Macromedia Flash files is, as well as my Windows Update/Auto Update .adm template. Don't ask me why, I looked them over, and they're completely normal as far as I can tell. If you can hide a keylogger in an .adm file, you're pretty clever.
"BackAttack" remote administration tool: Again, this is what it thinks of my .mfp file association in the registry, and all it contains is "MacromediaFlashPaper.MacromediaFlashPaper"
So, in conclusion, McAfee Anti-Spyware seems to be worth about what I paid for it, after rebate. :)