I asked Pepino about it recently, so I put my Deep Link Finder Script online. It's a simple Python script. Should run on Python 2.2 and up, possibly even Python 2.1 (but that hasn't been tested). The script is configured in the source code (I've added comments for it) and then simply called with multiple logfiles as parameters. It extracts from Apache Combined Logs which sites deep link to specified file types (configurable, some image types are set by default) and how often. It outputs an HTML fragment that you can add headers and footers to in order to put it online - for example, that's how my Zeitgeist page for deep links is created. The other pages have similarly structured scripts, except they collect search terms and general referrers instead.
I take a look at the deep linker list now and then, and if someone shows up there who deep links quite a lot and isn't an aggregator or news service, they get shown a corresponding replacement image. But really only those sites. It bothers me too when my feed reader suggests I'm an image thief or traffic robber.