It was this game which exposed me to the 856x480 resolution. Since then, I've started using 856x480 for other titles (like UT2003) with fantastic results.

Update: I've since learned that all games like this which use a Quake 3 engine, can be edited. Now I run RtCW at 1776x1000! See below...

To achieve 1776x1000 (or any other custom res), you must edit the wolfconfig.cfg file in the main folder. Use TextPad to edit the file since it can be hard to read in Notepad. Change the following lines:

seta r_customheight "1000"
seta r_customwidth "1776"

Make sure you change these as well to correct the aspect ratio:

seta cg_fov "90"
seta r_mode "-1"

Note: One or more widescreen video clips and/or screenshots of this title are available in our LIBRARY.

seta cg_fov "xx" - this line is unnecessary to change

Actually I had to change it in order to get the proper Field of View.

It is true that you have to adjust your fov if you want to have the exact same FOV with 4:3 and wide. But if you want to improve you FPS-gaming, you should not try to match the orginial FOV, but find the right one for you.

With better engines (like this) you can change your FOV with one keypress by using simple commands, as the best FOV changes with the situation (Sniping vs close combat).