Edge... it's been my experience if google is allowed in they assume all the rest of their little bots are allowed, too... hence if you DON'T want Googlebot-Mobile (example) you'd have to disallow that one.
I generally whitelist (allow) a handful of useful bots and disallow all others. Makes for a much shorter robots.txt !
6:56 pm on Apr 12, 2010 (gmt 0)
Each Googlebot crawls different data/media. There are places I don't want a particualr bot and other places that are OK.