Kevin,

Thats a great cloak for a live action role playing game. However, I'm with the others, it is a costume and there is no way to wear it without it seeming like one.

There was a thread about Inverness capes and apparently there are some band ones out there that are lightweight, rain proof, and neatly fold up into a small bundle when not in use. Hamish owns one so it has to be worthwhile.
Cheers

Jamie