Heh, Hookey, an old friend of mine -who also happens to be a teacher of creative writing- has that exact naughty habit. Each time I see her her notebook goes away stuffed full of my bleddy ideas. Each time I see her she also shamelessly advises me: "Well, there's no copyright on ideas!"
Mind you, it's my own fault if I fail to set the things down myself I guess..

Tam, good idea.