Google launched its online map service a few months ago, but this week they've added satellite image viewing as well.
Google Maps
Enter an address (street, city, state, zip) and view a map similar to mapquest or yahoo! maps. However, notice that the page doesn't have to refresh everytime you move around the area! Now click on 'satellite' in the upper right corner. The satellite images are amazing (well, if you're viewing a larger city). You can zoom in pretty far - close enough to find an individual house in Birmingham!