Good puzzles for PbP?

[Mazeburn]

So, I'm converting my RL game of Pokemon Tabletop Adventures to a PbP since my players have moved away and such, and I'm a big fan of puzzles. I was wondering what kinds work well in a play-by-post game? Riddles I'm sure work fine, though people have loads of time to think about them compared to in an RL game, and I can't think what else.

So yeah, if anyone has suggestions that would be awesome. :) Or if you can link to examples in games, that's good too.

Thankyou!

[Quietus]

I cannot stress enough : I Hate Riddles In RPGs. If this has been working for you in your pen and paper game, awesome, but they pull me out of the game and make Quietus solve the problem, not Ragnar the Barbarian.

On puzzles in general : I like things that are problem solving based. Pick a theme, or a schtick, and run with it. Designing a maze, for example, wouldn't really work in PbP; Designing a very SIMPLE maze with some kind of hindrance built in and a reason the players need to reach the middle? That can be a little more interesting, if done well. High ambient heat (a d6 or two per round) and some kind of method for slowing the players down (earth elementals in the walls, grappling/bull rushing them back?) makes them think about the terrain and work to get around it, without forcing them to solve the problem as themselves, rather than their characters.

[Mazeburn]

Heh, I think it depends on the puzzle personally. :] Can't stand the 'stop and solve this Suduko' sort thing. Should probably have mentioned, the format of my game is a desert island gameshow (where things of course go horrible wrong) so the puzzles kind of fit in.

You're right about the environment stuff, though, that would actually work really well for what I'm trying to do. Danke!