Can't vouch for how realistic this is in comparison to assembling a real puzzle, but I like the concept, and never shy from giving indie devs a bit of press. Developed by a programmer from Barcelona, Puzzle Man (now spelled correctly) varies from easy 24 piece jobs up to 300+ challenges. If you are into puzzles (which I am admittedly not), check it out for just 99 cents here in the app store...

I've tried! Great game!
I've tried! Great game!