Over this past weekend, I wanted to build something that let me text message the people around me – I recently moved back into a university dorm (for the incubator I'm in), and wanted to meet new people on campus by letting them know when we were throwing a party.<p>So I built Textius (with support from my teammates/business partners). It relays SMS messages to users who have checked in on Foursquare within 250m of you, essentially creating ad-hoc chat rooms. All in all, for a rookie Ruby dev, it took about 18 hours.<p>I wish there were some sample screens I could share, but this all goes on in users' phones. We had a 6-person test the other day, though, and it was actually a lot of fun!<p>What do you guys think?