Sid Meier's Railroad Tycoon was released completely free a couple days ago! Fileshack (my favorite game-related downloads site) has the game available for download, so jump on over and give it a go. Don't expect graphics like Open Transport Tycoon Deluxe (which is a graphical and gameplay improvement upon the original Transport Tycoon Deluxe), but it has its own charms.

I played around with Railroad tycoon for a bit, but to be honest, I've never really been that good at micromanagement games or real-time strategy games so I failed horribly...I have a hard time keeping twenty things going at the same time, something about a broken X chromosome or something...in any case, there's the link if you're interested, and enjoy!