A Russian developer is working pretty rapidly on Medieval - a WarCraft III clone for Pocket PC devices. Just a few days ago I downloaded an alpha of this program and it was unplayable. Today I grabbed version 0.1, and it's perfectly playable, if a bit confusing. For example, by default the program opens in landscape mode, but if you use your PDA's directional pad to scroll across the screen, it scrolls as if it were in portrait mode. If you switch your Pocket PC to landscape mode before opening the game, you won't have this problem.

If you want a more full-feature WarCraft Clone, you can check out n0p's Wargus port. It uses the Strategus game engine and WarCraft II graphics to make a WarCraft-like experience on the PocketPC. But it requires a huge amount of memory. In order to play on my Dell Axim X50v, I need to have more than 40MB of RAM free. You also need to have a copy of WarCraft II in order to play, and the setup process is rather complicated.

Medieval, on the other hand, is less than 1MB at present. All you need to do to play is unzip the file and copy it to your PDA. Now if someone would just create a StarCraft port, and not get sued into oblivion in the process, (although I'm certain plenty of people would be willing to pay for a licensed copy of WarCraft or StarCraft for Windows Mobile).