Google Desktop Search is out: http://desktop.google.com/

Search files, e-mail, AOL conversations, Word documents, cache and more from one search box -- with Google speed and accuracy.

After waiting 1-5 minutes to search my 400,000 e-mail messages in Outlook Express for something at least twice a day, I am very excited about this. Turning a 5 minute search into a one second search is amazingly useful.