Best Device For Gesture Based Input?

jotaeleemeese writes: "A few days ago there was a discussion about gesture navigation in the Opera browser, that prompted my to buy Black & White, download Opera and get the evaluation version of Sensiva. Being a trackball user, I found gesture navigation too cubersome, I found a mouse not much better either. Then I thought a pen based device or a touchpad could be ideal for this kind of input, but before investing my hard cash buying something, I would like opinions from /.ers that have already tried something with these or other programs using gesture recognition and what the results have been."