Unobfuscating Google Maps javascript isn't that hard. First, I copied two of Google's scripts to my server. You need the first one they have you link to, and also the script that the first one loads (this is the one in the upper-right box on Mapki). Using my text editor, I added line breaks to both after semicolons and end-braces. The first script isn't actually obfuscated, just minified, and it's not that long, so I actually went on to format the whole thing. Once I could read the first script, I only had to make two changes to it in order for both scripts to work from my server: I had to tweak the call to the second script from the first so it pointed to my version (in GLoadMapsScript at the bottom), and I had to comment out the key validation check (in GLoad). Then I linked to my version of the first script from my HTML page, and it worked like normal! Blam.
With Google's scripts under the reigns, Firebug's debugger made it trivial to isolate the function I wanted. I triggered a call to the function in a third script, and placed Firebug's special debugger keyword before the function call. That gave me a runtime debugger with which to simply step into Google's function. And with the script on my own server, I could then isolate the function in my text editor, format it, and poke it until it made sense.
http://javascript.about.com/library/blformat.htm