Speed Mechanics for Lead Guitar by Troy Stetina looks cheesy but contains gold for those wishing to build speed with a pick.
http://www.amazon.com/Speed-Mechanics-Lead-Guitar-Stetina/dp/0793509629
Honestly, if you're serious about building speed, this book is a must-have. Not because the drills are so much better than anything else, or something, but because it goes into the WHY of good technique, and looks at the physical aspects of fretting and picking and how to streamline them. For the $17 or so Amazon.com sells it for, it's a no brainer.
Something I do as a legato excersize (though you could pick it too, I suppose - I just like the legato sound) is to break scales down into six-note patterns. If you're playing 3nps diatonics, there are only a finite number of "shapes" you will ever play through. So, I practice them:
Code:
|-------3-4-6-4-3-----|-------3-5-6-5-3-----|
|-3-4-6-----------6-4-|-3-4-6-----------6-4-|
|---------------------|---------------------|
|---------------------|---------------------|
|---------------------|---------------------|
|---------------------|---------------------|
|-------3-5-6-5-3-----|-------3-5-7-5-3-----|
|-3-5-6-----------6-5-|-3-5-6-----------6-5-|
|---------------------|---------------------|
|---------------------|---------------------|
|---------------------|---------------------|
|---------------------|---------------------|
|-------3-5-7-5-3-----|-------4-5-7-5-4-----|
|-3-5-7-----------7-5-|-3-5-7-----------7-5-|
|---------------------|---------------------|
|---------------------|---------------------|
|---------------------|---------------------|
|---------------------|---------------------|
Repeat each of those four times or so before moving on to the next "shape." If you'll notice, if you follow the pattern of moving one note up a half step when you move from one pattern to the next, the next logical shape you'll come to is the one you started at, just transposed up a half step. So, go back to the beginning and work your way up the neck this way. When you run out of frets, reverse it and start going from the last pattern towards the first, working down by a half step each time you go.
Transpose this across all strings - because the angle of your fretting hand changes depending on whether you're on the treble or bass strings (particularly if you play a seven like I do) and part of developing technique is training your muscles, you really need to practice this everywhere. Pay special attention to the G and B strings, where the actual patterns change due to the M3 interval....
If you're into 3nps stuff, this should help you. Also, whatever you do, don't force it. Stretch your hands, keep them relaxed, and take breaks every 15 minutes or so. You can really fuck up your hands if you rush this kind of stuff, it takes years to build the technique you hear from guys like John Petrucci, Joe Satriani, or (especially) Rusty Cooley, so be careful and don't try to force it to do it overnight.