Shazam
 

TO ALL OF YOU WHO HAVE A SMART PHONE (excluding BB because they're sh*t!)

Theres a free App called Shazam which does exactly what you are doing here - you hear a song on the radio, put your phone near it and it will tell you which song it is.

I say its free but it isnt on the blackberry.

It will also show you the lyrics in the time its playing as well!!