Caller One, the earner of more than $3-million who defected from the Golden Jubilee Stakes (Eng-I) at Royal Ascot, England, and champion Xtra Heat are among the nominees to Calder's 'Summit of Speed' day program on July 13. The race card that day includes four six-furlong stakes with $1.3 million in purses. Xtra Heat tops the probable starters for the $400,000 Princess Rooney Handicap (gr. II) and Caller One is among the nominees for the $400,000 Smile Sprint Handicap. The two other stakes that are part of the 'Summit of Speed' are the $250,000 Azalea Breeders' Cup Stakes (gr. III) and $250,000 Carry Back Stakes.Carolyn Chapman and Theresa McArthur's 5-year-old Caller One won the Carry Back Stakes on the first 'Summit' day program in 2000. Included in his victories have been back-to-back wins in the $2 million Golden Shaheen en route careeer earnings of $3,184,500. Third behind Squirtle Squirt and Xtra Heat in the Breeders' Cup last fall, Caller One was withdrawn from the Golden Jubilee due to an infection. He may remain in England to contest the July 11 July Cup (Eng-I) or fly to New York and join other 'Summit' contenders on a flight to Miami next week.Other top contenders for the Smile include California-based Crafty C.T. and Echo Eddie; Aristides Handicap (gr. III) winner Orientate; Beau's Town, winner of six of eight career; and international star Nuclear Debate.A 4-year-old daughter of Dixieland Heat owned by Ken Taylor, Harry Deitchman and trainer John Salzman, Sr. Xtra Heat was voted champion 3-year-old filly last year and has made has made three winning forays to New York from her Maryland base this year. In addition, she finished third to Caller One in the $2 million Golden Shaheen in Dubai in March.Winner of 21 of 27 career Xtra Heat will be challenged in the Princess Rooney Handicap by Gold Mover, who has a 9-6-3 record in 21 starts, with earnings of more than $700,000.Also among the 13 fillies and mares named to the Princess Rooney are Hattiesburg, winner of the Azalea on the 'Summit' card last year; Prized Amberpro, who defeated Hallowed Dreams two starts back in the Valid Expectations Stakes at Lone Star Park; Nasty Storm.California-based Captain Squire, Listen Here, and Smooth Jazz are among the top 3-year-olds nominated to the Carry Back. Bold World, Proper Gamble, and Zawzooth rank high on a list of 27 nominees for the Azalea Breeders' Cup Stakes (gr. III).