A year ago, (and a couple months) I joined the A to Z challenge, and realized the potential traffic something like that could create. Many of the folks who stick around here are folks I met via A to Z.
I'd found out about the A to Z by chance, and realized that there's really no place to go to find out about things like blog challenges and / or blog hops or blog rings, or ... basically blogosphere events or groups.
So I (and my buddy) created one.
If you're into events or challenges, please go to http://www.JoinSomething.net and check us out. You can created an account, or even log in with your FaceBook account, and "register" events.
The site isn't exactly completed yet, and we've agreed that it's always going to be a work in progress, so new and better things will always be coming down the pipeline. We're always interested in input.
Please go check it out, read the about tab, frequently asked questions, post in the forums if you'd like.
I'd consider it a personal favor. :D