I got a couple of responses to my request for a Close Calls Map. The first was this tool on communitywalk.com (a pretty good website in it's own right). I like the site and the way it looks, with the bigger map and info balloons. It's a little easier to use and you can define what kind of incident it was.
The other one I got was on routeslipper. I can't figure out how to zoom it in on DC or how to remove a bad report (as you'll see).
Anyway, play around with these and let me know which you like better. You'll need to login to get access to either one. Once we pick one, I'll link to it from this site and then we can start to track collisions. This can help us to determine dangerous intersections and locations, which will help us to fix them.