Address Book lets you get a map of an address by looking it up on Mapquest. I prefer Yahoo! maps. Inspired by this hint, I whipped up a little script that lets me find an address on Yahoo! maps.
Paste the script into Script Editor (in Applications: AppleScript), save it as Yahoo! maps.scpt in your user's Library/Address Book Plug-Ins folder, and restart Address Book.
Once Google maps starts working with Safari, I imagine I'll be adding it, as well, as per the recent hint.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20050209223750880