Wrathmonk, it's now pretty well established practice for ALL HR depts, as part of initial screening, to Google the names of any potential candidates.
Take care, even when you appear on other people's blogs.
I now deliberately avoid being in group photos at weekend "refreshments". Once you're tagged on someone else's "social network" site it's out there on the net and you've no control (other than asking they don't post photos that you're in). Learned this the hard way.