http://www.dolphinstreet.com Can you play a 12 bar solo with only 3 notes? Well, sure you can! I am playing over a 12 bar blues in the key of A, and each time through the 12 bars, I play only 3 notes from the A minor pentatonic scale. It's not my best blues solo ever, granted, but it is a good exercise in itself, and the video may be helpful in demonstrating that you don't need to play a lot of notes when you are playing the blues.
It's all about phrasing and making musical statements. That's what great about the blues - you can play 3 notes over and over - slightly change the way you phrase those 3 notes every time - and voila, it can sound great. Practice playing fewer notes when soloing and see how you fare. (less info)