Touchdown works, but it's 20 bucks. The only other solution, as mentioned previously, is to go into your calendar, find the meeting, click on it, and then accept or decline. Very annoying. Meetings that are very far out or on my busy days can be hard to find. I had hoped this would be fixed with 2.1. I was mistaken. This really, really, really sucks. All the other phones can do this. In this case, Droid doesn't.