I need some help

[nittans]

I need to come up with a way of doing directional drop shadows. The normal drop shadow stuff in the layers is fine as far as it goes but what I am looking for is a way of making a drop shadow appear as if the light is coming from a particular angle and and is ONLY giving one shadow rather than a wider two or three sided shadow.

Any suggestions as to where I can find a nice and easy free tutorial?

Thank you in advance