Whenever I encounter writer's block, I distance myself from what I'm currently working on. I think it was mentioned in the first few posts as well, but it's a great way of dealing with every writer's bane.
Another, quite personal thing I have going, is to put myself in a situation I find painfully boring, and adding inspirational music to that.
Most of my ideas come from times when I'm not focusing on anything in particular and letting my mind wander. Such situations can be during lectures, bus/car/train rides, rainy days, waiting for someone or when you just don't have a lot to do. Go get your iPod, mp3 player or what have you, then put the tiny machine of wonder on shuffle and sever all connections to the present. Just let your mind work on its own, don't pay any attention or try to reason with it, just go with the flow of your own thoughts.
Personally, I think it's a faster version of developing characters, plots or scenes, since it comes spontaneously and in a jumbled mess of pictures, feelings, sounds and acts played by the characters.
Then, of course, there's the version where you draw inspiration from your surroundings. Maybe it's a beautiful landscape, maybe someone you saw on the streets, maybe something you read, watched, memories or something else you find close at hand.
The only problem I encounter with that technique, is that I let others influence my writing too much. That, however, I avoid by developing the plot or character further, overworking it into something vastly different from my original source of inspiration.