It's hard to come up with truly original ideas for games, but Spot! is certainly something new for the Pocket PC. The game is based on the traditional 'spot the difference' classic. You're presented with two almost-identical images from which you must find a handful of subtle differences. It's beautifully executed, with a quick tap to locate each mismatch and a clear onscreen display of your progress. If you tap the wrong spot you're immediately penalised, and there's also an option to work against the clock if you're feeling quick-witted.
The game has only a relatively small selection of puzzles, some more fun than others, but there's a huge number available for free download from the developer's website, which makes this a game with plenty of replay value.
Don't be misled into thinking it's purely for kids - it's just as addictive for adults, and a good way to hone your visual skills, too.