To start with, I've made a little Flash widget to come up with random game elements. I've stuck a copy in the header of my journal here. All it does is read in an XML file and output a random element every time you push the button.
I'm still thinking of what I should put in the XML file. It's fairly hard to come up with a decent list of elements. Here's a copy of the XML file if you want to see the current list (technically it's invalid as it doesn't have a header, but Flash doesn't complain). If you've got any suggestions I'd be happy to read them.
Edit: I think I'll spend a few more hours today playing around with Flash, so I've used the widget to come up with an idea - plants. I'll throw around some ideas and see what I can do.