Hey Bruce -
There really are a lot of fun ways to stir the imagination on a subject like this. Here's what I recommend:
1. Forget what anyone else is doing. If you can think of it quickly, and it doesn't impress you, write it down and let it go. Someone's already coding it, almost certainly. If you want to build a better-than-X application, great. Otherwise, put it on a list of ideas you thought of but don't care about, and move on.
2. Ask yourself what an Android phone *could* do, given the resources/services it offers, and play! Do you know the game where groups of people are given a simple object -- a carrot, a slinky, an unidentified desk thing -- and have to "make" something of it in a few seconds? Do that. Don't record ideas, have one. If you come up with something brilliant, it will stop you and make you take notice.
Example: have you seen the iPhone/iPod touch commercial where they use the
unit itself as a game control? You "steer" the appliance itself and the game responds to the change. That's so brilliant, so *simple* and yet so...obvious, in a way. People wonder they didn't have it before. That's the result of a little imagination, a little observation, and absolutely no worry about "wasting" time doing something people haven't thought to do before, or didn't have the technology to make happen.
3. It's important to have fun. Give your license to be lame. One person's lame is another person's accident is another person's idea is another person's blank stare. Don't ask how it is useful. Look, and don't ask. Make up.
Although you may not feel you're very good at imagining in a constructive way, it's not about skill. It's about learning to let go and work with what you have, not think about what you want. Don't try to fill the box! Just play with it, and see what happens.