Hotels and booking sites want your business -- and they are coming up with promotions to prove it. Two of the best: Now through Sept. 15, guests at Radisson Hotels & Resorts get a free Friday night stay if they also book a consecutive Thursday or Saturday night. Reservations must be made a minimum of seven days in advance (www.radisson.com/freefriday; 1-800-333-3333). BookIt.com is giving away a free BlackBerry or other smartphone or music phone -- valued at up to $349 -- with any booking on its website (www.bookit.com).