Ever need to view an area by zip code?

I was recently doing a real-estate search, and sometimes it's more convenient to search an area by zip code if you have large city boundaries. For example, Raleigh is huge but I know I don't want to search for a house on the south-east side of Raleigh. I can search by zip code, but how do I know the zip code boundaries? Well here's a great Google maps mashup that'll do the trick:

http://maps.huge.info/zip.htm