Here's a suggestion for the Guild Masters:
You alread have a place to find background music. How about adding a "Sound Effects" download/upload area to your site? I've never seen anyone posting MTM2 sound effects, and I always find myself making my own. (I am currently looking for a slow-ringing bell, like you hear on an old train or on a bouy.)
Things you will have to consider:
Point out your current "Sound" section, and note that MTM2 add-on sounds must be at least TWICE as loud as normal WAVs. So if they preview them in their browser, they will have to turn down the volume!
You might want to have subsections for "Continuous Sounds" (looping) and "Impact Sounds".
A moderator may want to have the option to "rate" the sound effects, noting things like "fuzzy quality", "very quiet", "excellent!", etc. so we can sift through all the "crash" and "engine" sound effects that people are going to want to contribute. Alternately, you can allow a forum-like link for author/user comments (to give credit to the original sound creator if you merely increased the volume level, etc.)
Whatcha think? Does this give your site engineers something new to have fun with?
Clawfford, the Big Red Cat
www.gameroom.com/clawfford