Today I sent out a little update to my friends and contacts about the recent galleries of mine on WIRED News. Unfortunately these emails went out with no Subject. This is due to a bug with Leopard's Mail.app. Basically if you have more than a few hundred addresses in the BCC field, the Subject line gets lost somewhere along the line. Here is a thread on the Apple support forums discussing it. Sorry to all the folks who ended up getting that email twice with no subject! Emails without a subject are a huge pet peeve of mine.
UPDATE 10.5.2 fixes this issue, thanks Apple!