I second
HiJackThis. Just be careful what components you remove with it. A few of them will be necessary system components. When in doubt, do a Google search on the component. As great as Adaware, Spybot, and the rest are, their spyware-removing capabilities are only as good as they're programmed to be.
Also, something useful to have on hand is
LSPFix. In the event you remove a piece of spyware/adware/malware/whateverware, and then discover that you can't connect to the Internet, LSPFix may be able to fix it. It'll save you the trouble of having to reinstall your OS.
And interesting link there Tom. I guess if people don't take the time to educate themselves first on what they shouldn't install, they'll just have learn the hard way. Latest news is that Grokster is in talks with Sony BMG. You could smell the greed coming a mile away.