I've been pondering the same question. I have been to several fabric stores around (never thought I'd be found dead in one!) and couldn't find the right material. The only material I found that was close to what I wanted was a suede, but I don't think it would hold up to the constant Texas Sun. I did go to a upholstry shop and the guy said he wouldn't cover it. But, he had tons of different styles of Tweed that I thought would look real good. I've seen many trucks done in Tweed, but not sure how hard it would be to install. Here's a pic of LOHRTBT's Tweed dash.
http://www.geocities.com/yudlooz.geo/interior.html
I've decided just to buy one of those carpet dash coverlays until I can replace my dash. Mine's so cracked, I don't think it will cover well and look good.
Let me know what you decide!