Check out Jason Becker, an amazing guitarist who is a BIG influence for a lot of the world's top players. There are a couple of lessons and downloadable mp3's on his website www.jasonbecker.com
This guy opened my eyes a lot and I really started improving when I spent time listening to his music and studying how he put pieces together.

Another piece, probably way above your current level but a great goal to practice towards is "No Boundaries" by Michael Angelo. It covers just about every technique you can imagine in a rock/blues/neo-classical influenced framework. You can download the whole track on www.angelo.com and if you like it, you can get the instructional dvd which breaks the whole song down section by section with in-depth explanations of each technique used. Bizarre lookin guy and most of his other stuff is unlistenable, but it's a great track. If you can nail that one then you're technique will be world class.