this isn't always guaranteed to be valid from site to site, so I'm not sure how comfortable I am adding this in.  it's likely uncommon that m.* isn't a mobile site, but it can happen.

also, if we're going to add anything that automatically redirects users, I think we need to make it an optional feature as it may frustrate some users.

would certainly be interested in feedback from others... @andytuba, @gamefreak, @mc10 ?