Lifestream plugin for WordPress that gives you a tumblr-esque activity stream aggregated from multiple locations. Slick.
In one place search yahoo, Google, Technorati, WordPress.com, YouTube and lots of others. Punch in a term, see the top results from a whole bunch of useful sites. Great idea. Hat tip Seth Godin.
Alltop is a series of one-page-aggregations based on popurls.com. It's put out by 3 people including Guy Kawasaki in a company called Nononina.