This fun thingy (url will break sooner or later, as the Quake Archive upload folder is rearranged, in which case you can find it in some other subfolder there), is something I'd like to call SuperTraceWalk. Those of you who have ever messed with bots or other types of AI, might know of a phenomenon called tracewalk, which basicly does a bunch of tracelines (or traceboxes) to simulate walking in a direction as a check for accessability. However, it had limitations, and wasn't very accurate. This version simulates client walking, very accurately, but limited to engines which support SV_PlayerPhysics, tracebox and possibly something else (tested in DarkPlaces and FTEqw). Requires also some changes in SV_PlayerPhysics, to override some tests which would otherwise fail the function. I've included here sv_user.qc from the DP site, with the required changes. The required dpextensions.qc is found in a DP engine zip. In the compiled progs.dat, impulse 100 fires the test command.
Have fun!