Ok first of all set goals for yourself. "Playing fast" is a term that can be used extremely loosely. For example, you may say that Stevie Ray Vaughan is a fast player, but put him up to Yngwie and he's like a tortoise. Make your goal as specific as possible, eg, I want to play this lick at 150 BPM, or this scale on all 16ths at 200 BPM or sweep arps all 16ths at 160 BPM... etc. You can have more than one goal at once. Once you have achieved your goal, make a new one - that way you will always be improving yourself.

Now develop a routine to practice with. Get a metronome, have your goal in your mind (or written down), and write down a practice schedule that goes along with your goal. Here's some pointers for helping you do this:

-Always spend at least 15-30 minutes warming up. Get some good warm up licks and patterns off of this site or another, stretch your hands out, then do the licks at a very slow tempo. You have no idea the benefits of warming up properly.

-If your goal is to play a certain solo at a certain speed, do not spend the majority of your schedule working on that solo. It may seem tempting, but if you have a half an hour of other stuff, then an hour of working out one lick, the lick becomes tedious and boring. This doesn't seem very bad at first, but eventually you'll get so bored that you won't pay attention and become sloppy. I would only spend 30 min. max on this part of the routine.

-Work on scales for awhile. Don't limit yourself to just one pattern though, find one scale and try to figure out patterns all over the neck. A lot of fast playing you'll see is just ripping up scales and arps., so you might as well go to the source. One good thing to do is to practice scales while watching TV or reading a book, because it'll work in subliminally. You'll go back to the guitar and find that you know the patterns by heart! If youi feel so inclined you may spend an hour or more on scales.

That's all I have to say about the technical aspect of routines (except you may want to insert things lick working on vibrato, tapping, arpeggios, legato).

Now while you are practicing - remember to play slow and work it in the muscles (I know, it's a redundant thing that everyone tells you). Play cloes attention to your picking technique while you practice to, make sure that if your going for alternate, you're doing strict alternate picking. Same for econ... etc.

Ok I'm done. Hope that helps!