Apply pressure (particularly to your artery if you can, but if not, at least to the cut) & see if that helps. Elevate your leg above your heart.

http://firstaid.about.com/od/bleedin...ingsteps_3.htm

A hot cloth can sometimes help as well. And/or you could create a tourniquet (sp?)

Here are some more ideas:

http://www.ehow.com/tips_116346.html