Also, in soloing, I always to try and keep in mind that listeners don't wanna hear all the scales I know. I remember reading somewhere that you wanna make the guitar "talk", and I always try and remember to do this. Also, when soloing/improvising, I always try and string together small runs or riffs that, when added-up, are a complete solo. It's alot to remember, but worthwhile when it all comes together.
Improvisation/soloing or jamming with another guitarist or guitar players, no matter what their skill level, is a great learning tool about your playing and gives you new ideas, inspiration, and approaches to playing.