Late yesterday, Erik Clapp, the fellow slowly but surely archiving all of Bobbie Wygant's chits and chats for KXAS-Channel 5, sent word that he'd just posted to his website golden-oldies featuring a cigar-smoking David Letterman and Jay Leno. Wrote Clapp, "Since it's Conan week and all, thought you might like these!" Much obliged. The Leno interview, from his Tonight Show guest-hosting days in '87, follows. In case you forgot all about Collision Course.