irclean: You might try the Kool Stop Chain Disc:
http://www.jensonusa.com/store/produ...hain+Disc.aspx
It took me a few minutes with WD-40 and a fingernail to get rid of the dopey logo, it looks OK now. It comes in different sizes to fit the chainwheel size so make sure you get the right one. Since there is still the distant possiblilty of catching your pants leg with any guard of this type I still use an ankle strap. I'm a belt-and-suspenders kind of guy.
Or you might look at the Hebie line of chainguards:
http://www.hebie.de/Chainguards.6.0.html?&L=1 German engineered.