Here are some useful links for anyone more interested in this topic.
I have such an 10$ device at home too, quite some fun playing around with it.
Btw McDonalds: You can also hear drive-in rf communications.
http://www.rtl-sdr.com/ Very informative rtl-sdr blog with lots of tutorials
http://sdr.osmocom.org/trac/wiki/rtl-sdr – Official rtl-sdr osmocom website
http://www.reddit.com/r/RTLSDR – Reddit rtl-sdr forum
https://groups.google.com/forum/#!forum/ultra-cheap-sdr – Google groups forum
http://www.sdrsharp.com – SDRSharp official website
http://www.rtlsdr.org – RTL-SDR community Wiki
Here` s another nice one. This is a websdr, which means you can make use of a web interface on which you can control other peoples SDR with bigger antennas attached.
http://websdr.org/