Billy Goat Tavern, the grungy burger place that inspired the famous "Cheezborger Cheezborger" skit on Saturday Night Live, is suing a Florida based restaurant chain, called Cheeburger Cheeburger, for trademark infringement. The chain has existed since the mid-1980s, but a plan to open a store in Glenview spurred Billy Goat to sue. (In a related story, we neglected to report that Bill Churachas, the long-time cook at Billy Goat, died in late October. He will be missed.) [Trib. log-in: gapers/gapers]