I have created a new Google/Address Book script, based on the excellent AppleScripts from the Map Address Book addresses via Google Maps hint. This new script uses the first address in your "me" card to get directions to the selected address. I also added comments so that folks unfamiliar with AppleScript can figure out what's going on.
I've also gone and combined the best of both of those originally posted "map this" scripts into one new revised "Google Map of" script. I've created an installer for these scripts, and placed it (and the scripts) on my site. Thanks go to Unixjunkie and MikeD for their work!
[robg adds: I haven't tested the installer, but I did test the revised basic mapping script (works great). But the reason I ran this as a new hint is for the Google directions script. It worked perfectly using some test addresses in my Address Book. According to Google, I'm "one day and 15 hours" from my dad's house back east, assuming I don't actually want to stop to sleep :). I have placed both the revised Google mapping script and the new Google direction script on macosxhints, just in case they are no longer available at the above URL. I have not mirrored the installer.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20050212174002477