Open source business simulation game based upon Transport Tycoon Deluxe. Online multiplayer games are available, as well as a single-player against computer.
You can calibrate touchscreen from the "Mouse emulation" dialog in the startup config, if you cannot hit buttons at the edge.
How to play: http://wiki.openttd.org/Tutorial
This game is open-source - you may find sources at http://openttd.org/ or at my website.
This game is not affiliated with the original Transport Tycoon Deluxe game, and does not contain any content from the original game.