Google has announced search history, and unlike your browser’s field history, it’s attached to your Google account, so it’ll follow you around between computers.
So, let’s see, we’ve got email via Gmail, news headlines from Google News (including personalised news alerts), discussions in Google Groups and now your own search history. How long before a fully-fledged portal brings them all together onto one page? They could call it MyGoogle. (Whoops, they’ve already registered it…)