Got a cheap rasberry pi recentently. Since the httpd on it was not eating lot cpu cycles decided to run something else that will give use to my rtl-sdr as well. Is called pi aware [1]. So far got interesting ADS-B statics from my place [2]. Not bad.

As a side note use rtl-power as a passive radar could be another interesting option, just for the stats ;-).

[1] http://flightaware.com/adsb/piaware/
[2] http://flightaware.com/adsb/stats/user/kristianpaul