Field of View
Field of View or Field of Vision (FoV) is the angle of your view in the world.
Changing the FoV will cause the view to zoom in/out. A smaller FoV would be more zoomed in.
You can set the player's FoV by setting Pawn (UT).FovAngle or calling PlayerPawn.SetFOVAngle (the latter is replicated to clients, the former isn't).
Phantasmagorium: Wouldn't it be possible to use a key bind to, say, z, and have that set to edit your FOV so that you zoom in with weapons with no scope? I seem to remember being able to do this before, but forget how to set up UT2k3 so I can do it. Hehe.
Foxpaw: You can do that, but I believe setting your FOV is considered a "cheat" and has to be expressly enabled on the server to allow it. On botmatches it should work fine.
Phantasmagorium: Thats mainly what I do, seeing as even with my DSL I lag really bad sometimes. It's funny to take the rocket launcher and blow off a snipers head though :)