If anybody here has ever played Counter-Strike: Source or any other Source-engine game, you will know and love/hate surf.
WELL! I finally got around to learning GTKradiant, and created a neat little demo map based on surf in CS:S. I can get most of the functionality, but some things about player movement couldn't be replicated. I'll post the map in a minute.
It absolutely will not work without a specific set of variables.
sv_airaccelerate 100(0)
sv_friction 3
sv_maxspeed 200 (400 worked, just not as well)
Also, due to Quake game mechanics, you have to be looking away and down from the ramp (like a step in strafejumping). This keeps you from flying off the top of the ramp.