Great idea for a reality check Froggeh,
As the more things a person can find to use for reality checks, the better chance they will have of finding one that may actually work.
For me it seems like the best reality check is just to try to be aware all day long of whether I am dreaming or not, no matter what I am doing, as this seems to create the same kind of consciouseness in my dreams when I am lucky enough to just suddenly be aware that I am dreaming. Just trying to maintain this awareness all day long though is a chore.