How to increase guitar playing speed fast?

Here is a link that might help you... How to Build Speed on Your Guitar | WriteNiche (http://wn.goldenprose.com/?q=node/337)

The site referenced above is good!

A few other tips from me would be to spend a lot of time practicing to be as accurate as possible slowly and then increasing your speed by the use of a metronome as mentioned on the site above. The use of the metronome is a good idea because then you will have something as a marker for your tempo as you are practicing.

If, when increasing the speed of the metronome, you start to make a lot of errors, then I would suggest setting the metronome to a slower speed where you are still challenged, but then making fewer mistakes. If you set the metronome too fast so that you are making a lot of mistakes, then you are defeating the purpose of using the metronome in the first place.

Just please remember that it's not just practice that makes perfect, but perfect practice that makes perfect! There are plenty of bad ways to practice doing anything.

If possible download guitar pro, power tab or similar software.
These are great as you can adjust the tempo of what you are playing and with guitar pro it even has an speed trainer, wich gradually increases the tempo through each loop.