Growing up I had a set of Pentominoes and a rectangular tray in which they could be placed. I may even still have it somewhere. It's got to be more than 35 years old. Hmmm... I guess it would be pretty miraculous to find it tucked away in a box after four or five major moves (including one from Canada to the U.S.).

Recently a friend gave me a puzzle set with pieces that include some pentominoes and some other things. It seems to have a lot of solutions. Here's one of them: