http://virtualearth.msn.com

Things I like so far:

• Dynamic searches as you move around the map.  For example, I can search for "Starbucks", and as I move around the map it dynamically scopes the query to the area which is visible.
• Hybrid street name/aerial view. 
• Ability to have multiple searches at any time

What I don't like:

• I made the mistake of installing the "locate me" helper application.  Apparently this guy only works with Wireless connections, and since I am on my wired connection here in my office, it doesn't work properly.  I can't seem to figure out how to disable it though and just do a regular IP lookup.  I think the app should be smart enough to realize though that a wireless connection is not available and fall back to IP lookup on its own. (Update: As Mattew pointed out in the comment, it seems that my experience has been less than optimal here in that both the Locator tool and IP-based lookup are failing... in fact it does do exactly what I want to do).
• The mouse scroll for zooming in and out is awesome, but I think it could be a bit smoother.