[slmbrhrt]

For generating roads or waterways, try coming up with rules similar to the way they're created in real life. For example, water flows downhill and pools when it finds a local minimum. Roads, on the other hand, tend to avoid steep grades when they can, typically moving straight and branching at right angles at regular intervals.

Read up on L-Systems, too. They're great for creating organic structures, be they leaves, trees, or river-tributary systems.

Oh and this may be useful: http://roguebasin.roguelikedevelopment.org/index.php?title=C...

[alaricsp]

That rogue-like cave generation algorithm isn't the kind of terrain I'm after, but is nonetheless quite awesome in its results. I'm now wondering if I can find an excuse to involve caverns in my game ;-)