From what I've heard (no personal experience here), Scots tend to wear the kilt on weekends. So if you're going to be there on a Friday or Saturday (why would you go for less than a month?), bring a kilt, wear it, and get a pint (hopefully for free) at the pub.

A friend of mine told me a secret about being in a pub in Scotland: bring along a 6' tall redhead and neither of you will pay for drinks. I've got my redhead, anybody else?