I started up a database of problems and solutions for physics, chemistry and maths. Take a look http://toxicopoeia.com/?get=problems&cat=physics [Broken] I've only added physics questions at the moment. All the variables are randomly generated so people can keep practicing the same kinds of questions. I only just got started with this I'm planning on throwing in things like function graphers and diagram generators. If any of you want to see any physics/chemistry related questions added tell me and I'll throw them in. Also if you wanna add a question can you write out the solution yourself because it takes me ages to do the solutions.