Soldier of Fortune

Easier solution.

Go to page below and dowload SoFplus mod. Adds panoramic resolutions in the game menu.

http://sof1.megalag.org/sofplus/

Thanks to triplesick for posting this solution...

Getting a widescreen resolution in SOF1 can be done using a hex editor like this one. Search the .exe for 80 02 00 00 E0 01. This is the 640x480 data. Change it to anything according to the hex editor tutorial, you may check this thread for the List of Hex Values for Common Resolutions.
For example, you can change it to "90 06 00 00 41 0a" if you want a 1680x1050 resolution. Then select 640x480 in-game, and it will render in 1680x1050.
It's vert-, but the hard-coded FOV is 95, which I think is perfect for widescreen in a tactical shooter.

There is one notable bug with this solution, which is that the menus are clipped off. In between missions, you need to change to a 4:3 resolution to click the "accept mission" button :-/

Two side notes:
1. Enough of the source code has been released as part of the game's SDK to code to a more-or-less proper widescreen patch. However, the source should be compiled with Visual C++ 6.0, which is completely broken in Windows 7. Otherwise I'd do it myself.
2. I highly recommend using the "MarkC Windows 7 mouse acceleration fix" for this game. Otherwise, the mouse acceleration makes aiming difficult.

Note:
Menus are clipped off. In between missions, you need to change to a 4:3 resolution to click the "accept mission" button.