Do you like to do jigsaw puzzles on the computer?

I don't think it's a waste of time. If you enjoy doing it, then it isn't a waste :) Personally, I prefer having the physical puzzle pieces rather than doing jigsaw puzzles on the computer. I like to separate the pieces and I find that when doing one on the computer, the program doesn't have a lot of space on the sides, so the pieces get in the way.