Ah, to be able to ride the smaller bike frame! I can see how it's possible to work around (or with) the rules when the frame is pixie sized.

However, for those of us riding 61 cm or greater frames (without S&S couplings, at any rate), we can't exactly pull these tricks. So be happy that you're not part of the "too tall for most brand's frames" contingent.

That said, the "sporting goods" tactic could work - so long as your case doesn't have any decals on it that suggest a bike, cycling, or otherwise. My club's Iron Case is festooned with multiple decals: USA Cycling, randonneur club decals from multiple countries, Tour de France, etc. It essentially screams "this is a bike!"

I know that kind of suggests that I buy my own case. However, as I live in a tiny apartment where space is at a premium, and the bikes alone take too big a chunk right now, owning my own case isn't in the cards. But when it is, it'll be "sporting goods."