Battle.net Ding Broadcaster does what the name implies... AND NOW EVEN MORE!
When your character dings or (optionally) gets a new achievement, it sends a Battle.net broadcast announcing what you have done to all of your RealID friends. After all, why manually take the time to spam your friends as you level an alt from 1-10 or do an instance for the first time when you can have a mod do it for you?
The mod will currently send out broadcasts when you level up or get an achievement. If you think there's something else that it should be able to broadcast, let me know.
I created this mod because patch 3.3.5 had been out for a whole day and there weren't any mods available that took advantage of the new features. I'd never made an add-on before, but I thought I'd give it a shot.
Achievement broadcasting is off by default, type "/bdb achievements true" (without the quotation marks) to turn it on.
Version 1.1: Added the option to broadcast achievements (/bdb achievements true). Currently off by default.