Solving problems is fun! The harder the better. Here is a small selection of good ones. No solutions are provided here. You just gotta solve it. Here they are sorted by a somewhat arbitrary level of difficulty:
Geese Eggs
Unfaithful Women
The Underwater Cable
Links to related sites on the Web
Yahoo Recreation:Games:Puzzles
If you know of a nice logical problem please fill in a comment form or E-mail me.