Every now and again, I find myself working from behind a firewall and fall back to using Gmail. When I do, I BCC myself on all messages I send (because my POP3 server receives all email and its archived from there and Gmail is just a backup).
I noticed one day that because someone had started addressing me as “‘JavaMan’ <ben@…>” that Gmail decided that my new name was in fact ‘JavaMan’ and whenever I CC’d or BCC’d myself on email, it would use that alias. BCC doesn’t matter, but for CC’ing, it’s actually a pretty embarrassing moniker to start sending around.
I played around with it a bit, and, sure enough, you can override the names associated with any Gmail contacts by simply sending someone an email with the email address given a new name (like ‘ILovePresidentBush’ <yourfriend@gmail.com>).
Of course, I don’t imagine folks are addressing themselves via CC or BCC that often from Gmail, but if your new name for your friend sneaks by just one time… 😉
Update: Matt Raible commented saying, essentially, “Any email client lets you change the name associated with an email address — just change the value in quotes.” Let me be clearer: Gmail lets you change the name associated with an email address in someone else’s address book permanently (until that someone else changes it to some other value, or someone else changes it). In my case, I didn’t change my own name in my address book to “JavaMan”, but because someone else sent me an email calling me JavaMan, now its changed in my address book.
Ben Galbraith 
You can actually do this with any e-mail client that allows you to modify the name in the quotes. For example, change “Matt Raible ” to “Montana Hick ” and it’ll come through like that.
Completely off-topic, but I couldn’t find your email to ask you this question… a little while back, you published an article about javascript frameworks. How did you create those bar graphs? There’s a really cool, subtle texture to each of the bars that I really like.
Thanks!
Matt: Err, you’re misunderstanding me. You can change the name of any of your addressees using any email client, of course. What Gmail lets you do is change the name of anyone in someone else’s Gmail Address Book — permanently (until they change it back).
For example, imagine if someone sent you an email addressing you as ‘Montana Hick’ <matt@…> and it changed your name to ‘Montana Hick’ in your local address book. That would stink.
This doesn’t happen with Apple’s Mail and Address Book. It goes with Gmail.