(Shameless plug) For an arduino based roving robot project:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1173623665
I also have a BS2, but since I got the arduino, I don't use it any more. Arduino is much more powerful (analog in, hardware serial, hardware PWM, 1k ram, 16k flash), I mean, arduino has 1 kilo byte of RAM, the BS2 only has 26bytes, and only 4k flash memory! But the BS is much better documented.
Cheers,
-Z-