Not only can radio host Don Imus talk up a storm but, judging from recent events, he's also a dab hand at autographing. Immediately upon Villard's May 28 publication of Two Guys, Four Corners, a collection of southwestern photographs by Don and his brother (and frequent guest) Fred Imus, the I-man began talking up his tome. Results were immediate: the book went back to press twice; it now has 110,000 copies in print. But the real bonanza came when Imus and Fred (a real draw on the tour, as many listeners don't believe he even exists) embarked upon a two-week autographing blitz. With sales never dipping below 750 books at each of the nine events, the highlight was an 11-hour, 3200-book marathon at R.J. Julia in Madison, Conn. The day before the event, Imus told his fans in 88 markets around the country they could phone in orders to be shipped. By noon, store personnel had taken 800 phone orders; realizing that the supply of books couldn't accommodate those orders plus a live crowd, the store arranged for 1800 copies to be brought in from the RH warehouse and a store on Long Island. In addition to signings and Imus's persistent plugging, Two Guys has been featured on 48 Hours and Today, as well as in USA Today and the New York Daily News.