Users continually increasing??

People have probably seen this in the past but I just saw it today here. In the last few minutes I've been on the site the # of anonymous users has went from 130 to over 300. Could this be the elusive GoogleBot? Any other possibilities?

Ya, it's most likely either a commercial bot that I haven't written the code to exclude, a opensource bot of some kind or some other bot-like activity that I'm not handling.
-dr