I was just invited to an event using the DialedIn.com service and I noticed something interesting on their mobile website. It turns out that they have a BlackBerry client available for their service. Personally I have no friends 
but I am sure some of the more social BlackBerry users could find a use for this. The interesting feature that is mentioned in the install link is that this application will allow you to sync up to 500 of your BlackBerry contacts to DialedIn so that you can invite them to your next party.
As a sidenote DialedIn seems to be mobile friendly compared to Evite which looks terrible from my BlackBerry. (Javascript hell!) DialedIn is so mobile friendly that it even lets you create events from your BlackBerry and invite people through SMS and email.
Website: http://dialedin.com/
WAP Site: http://dialedin.com/wap/
BlackBerry Client: http://dialedin.com/blackberry/index.html
