Looking at one of sivason's threads, I was thinking about how many people have their own unique reality check. So, what reality checks have you used and which do you use now? If you use one that's not so common, please explain it.

For me, I started with the finger through the palm RC and counting fingers. They never got me lucid though, probably because though I was consistent throughout the day, I was just getting into lucid dreaming then. I then change my RC to the nose plug, which I mostly use to confirm i'm dreaming rather than question if I am dreaming or not.
These days, I don't really use a physical RC, it's all mental. I just "feel" the dream with my mind.