Search your own computer "Google Desktop Search is how our brains would work if we had photographic memories. It's a desktop search application that provides full text search over your email, computer files, chats, and the web pages you've viewed. By making your computer searchable, Google Desktop Search puts your information easily within your reach and frees you from having to manually organize your files, emails, and bookmarks."
Google Desktop Search Launched "Indexing is fast and only happens when your computer is idle...Get a new email? Visit a new web page? All this information is automatically recorded and made searchable within seconds."
"Each time you view something, a snapshot of what you've seen is created. Did you visit the same web page several times in a month? A copy of the page each time you visited is made. The "1 cached" link will change to reflect the number of copies recorded."
While support is incomplete, this article mentions that other file types, "Images, Acrobat, Windows Media and MP3" are indexed. This probably suggests future features.
The most important missing feature seems to be, failure to capture metadata or allow you to modify it. What a wasted opportunity. There's no advertising but hopefully this can stay as a way to integrate people's desktops with the web site and not have to become its own money spinner.
Another article with screenshots, "Google Your Desktop".
AOL is going to do the same, curiously "...the desktop search tool is being tested alongside the AOL Browser but declined to elaborate further. She said the AOL Browser will launch as early as November."