I’m sharing a room with Chad Dickerson here at eTech and he was up until the wee hours last night and up again at the crack of dawn putting the finishing touches on a prototype called Checkmates. The application, which runs on your cellphone, uses a combination of APIs to show your location superimposed on a map along with the locations of your Flickr friends (as long as they also have the Checkmates running and have declared their location.
For eTech, Chad posted this morning about the Checkmates and mentions a special overlay where you can declare your location on an eTech map.
I’ve run into a snag b/c my Sprint cellphone won’t let me run my web browser while in Digital Roam mode (reception is not so hot inside the conference hall). I’ll try and install it later.