UPDATE - 10/20/08:
1. I tested version 2.36 from the latest stock Titan ROM released. Version 2.36 will constantly redirect you to a web page if you do not pay for tethering!!!! Stay away from it.
2. Updated bad .dsm file, it had an invalid GUID in it that builddsm.exe didn't overwrite.
3. Added wmodem.htm help file from verison 2.36
4. Found new driver installer program to automate driver installation. (New Screenshot)
Tutorial: http://forum.ppcgeeks.com/showthread.php?t=11146
WModem 2.25 - found on the net somewhere
Drivers for XP and Vista 32Bit - I have been using this version of WModem and these drivers with my Titan since December to stream TV from home to my laptop at work. I have not used the Vista drivers yet, so if someone could try it out and post results... that would be great.
I take no credit for this OEM other than the creation of the provxml file to ensure the registry settings persist when cooked into a ROM, especially with the kitchens as of late.
EDIT(old): Created cab version per request, I have it built into my current ROM so I couldn't test it. Please post if it works.
EDIT(old): While searching for more drivers I found this post on ppcgeeks:
http://forum.ppcgeeks.com/showthread.php?t=11146
I remember now that this is where I found these files to begin with. There is a great write up as this is a tutorial thread.
All credit goes to these guys, I just packaged the stuff.