HijackThis, a general homepage hijackers detector and remover. Initially based on the article Hijacked!, but expanded with almost a dozen other checks against hijacker tricks. It is continually updated to detect and remove new hijacks.
It does not target specific programs/URLs, just the methods used by hijackers to force you onto their sites.
As a result, false positives are imminent and unless you are sure what you're doing, you should always consult with knowledgable folks (e.g. the forums) before deleting anything.