Well, one can ski on a gravel or sand bank with regular skis, if it's steep enough!

Have you seen the Turfboard? I've seen people using them on mountainbike trails at Killington, VT. Maniacs, really. I think those would work pretty well on your hill if you're in need of a good frightening.

I know there's a few British skiers/boarders out there, I assume they're a rather determined bunch, not having met one in person.

-Zeke