Quick idea!
I've seen your iron-on letters you sell on Ebay. Very cute!
Why not, instead of having a fundraising program where you sell shirts, you sell just the letters? This would especially go over well at colleges with a good number of locals, non-socials (like SAI, TBS, DO, APO, etc).
Just something to consider.
Also I'm fixing to PM you about something different but on the same lines. So check your box!