BURBANK - Former Tennessee Sen. Fred Thompson is scheduled to be a guest on "The Tonight Show with Jay Leno" tomorrow, a day before officially declaring his candidacy for the Republican presidential nomination. Thompson's appearance -- he last appeared on the show June 12 -- will come on the same day as the eight announced Republican candidates debate in New Hampshire. The Thompson campaign announced last week that he would declare his candidacy Thursday, with a Webcast on his campaign's Web site, www.imwithfred.com, then conduct a five-day campaign tour through Iowa, New Hampshire and South Carolina, all key early states...