Most people will never tell you this. I've been playing guitar for over 40 years and speed comes from two main points: 1) Practice and 2) Physical ability. The advice others have given you regarding keeping the movement short is sound. Try not to move your fingers too far from the fretboard. Keep them as close to the string as possible. Practice a movement slowly at first until your fingers "remember" the pattern and then gradually speed it up. Also, watch your picking hand. Are you using efficient picking patterns (e.g. alternate picking)? Are you using hammer-ons and pull-offs? Do you have the raking technique down? Secondly, even if you practice, practice, practice, you may never get the speed you want. Look at SRVs fingers...short and stubby. Physically, you may not have the right characteristics in your fingers, muscles, reflexes, etc to get the speed you want. You may be limited by your physical characteristics and you will never get there. On the other hand, watch BB King and some of the great blues players. They didn't have blinding speed but they did have soul. That's what music is all about...soul and passion. Keep playing and use the soul...afterall, expression is the most important part of music, not whether you can out-pick the next guy. There's always a faster gunslinger.