I found a great (free, and open source) puzzle collection made by a fellow called Simon Tatham, who works at Cambridge, UK. There's 32 puzzles in it at the moment, including Sudoku (called Solo), Futoshiki (Unequal), Nonogram (Pattern), and Mastermind (Guess). You can get them here. They work on Windows, Mac OSX, and Linux (they're even in the Ubuntu repositories!). There's also mini-versions on the iphone, ipod touch, palm, android, ans symbian s60