This approach has some drawbacks. For one thing, you don't want to do it if you're on mailing listswell, you could, just make sure you verify those addresses manually first. For another, it seems to be much more of a Club than Lojack solution, as, if enough people do this, the spam scripts will figure out a way around it (although, I like that SpamArrest makes you do one of those "type in the word that's in this obscured graphic" thing that makes it a lot harder for scripts). Also, it might be a little annoying to some people (which is why I put it only on my personal account, and will probably keep it only there).
In general, I like a server-side solution, though. Since I check email from multiple locales and don't always have my spam-killing-client-software of the week running. Also, it makes getting my mail a lot faster.
Here's how it's doing so far. Out of 76 messages, since yesterday afternoon, 2 were verified non-spam. Actually, one of those was a test from me. Nice.