Toy maker NECA demonstrates its replica Portal gun in this video. It lights up in both orange and blue, and makes appropriate Portal-y sounds! In short, the toy does everything you'd want a Portal gun to do ... except for the one thing you'd want an actual Portal gun to do.
NECA notes on its Twitter page that pre-orders in the US are currently sold out, but "other opportunities" are coming. Perhaps you should keep an eye on that Twitter page for your next chance to get in a clicking race with other ravenous Valve fans.