I never used it. As a warrior it is quite irrelevant (Frost on a weapon gets 'm all <img src="/ubbthreads/images/graemlins/badsmile2.gif" alt="" />). As a mage though, I'm sure it's a good skill to train.

I am in blood
Stepp'd in so far, that, should I wade no more,
Returning were as tedious as go o'er.