Everyone agrees on this: remote-controlled vehicles are freakin' cool. While autonomous agents are what we're really all about at Tabletop Robotics, we decided we had to build a remote control program for the 3pi. At this point we were using wired serial communication, but we decided to step it up and go wireless. This required a lot of soldering, but we were up to the task.
From our serial data classifier, we derived another serial application that would send data in response to keypresses. Specifically, the user could press the arrow buttons on the numeric keypad of their computer to control the 3pi robot. Although this program can be run with the easier-to-solder wired serial communication, for best results (and happier operators), we really recommend moving into the realm of wireless serial, if you're comfortable with soldering.
Download Project Tabletop source code (which includes the remote control program) here.