After more searching, I found out where so much of my bandwidth is going. Some pigfucker on myspace is hotlinking to an image on my web site for their background on their profile page. And current access logs are showing over half my web requests for that one file. So I’ve deleted it.
Now to work on getting a plugin to reduce hotlinking – it’s a problem I’ve let slide, but I’m seeing more and more hits to my site for people stealing my bandwidth, and I’m going to have to pay extra for hosting this month because of it.