Beyond DC, Track Twenty-Nine, and Greater Greater Washington, but rest assured that as soon as I figure out a half decent manner to present it to you guys, I'll be throwing my hat into the ring.
In the mean time, I encourage you to sign the petition (via GGW) supporting the Purple Line. I'd love to see it get started in New Carrollton and built westward if MoCo doesn't find a way to make it happen soon. Perhaps a successful stretch in PG County will silence the naysayers, perhaps even make a few more people start asking for it once it is build and working somewhere.
If anyone has any tips for making my map, I'm all ears. Until then, I'm still screwing around in Google Earth. If you want a sneak peek, I mentioned some of the basics in an open thread at GGW.