Big-box retailer Best Buy (BBY) is going small in an effort to reap sizeable sales of smartphones. The company is opening slimmed-down stores -- up to 3000 square feet -- exclusively devoted to the sale of wireless equipment. The reason: Apple's (AAPL) iPhone Research In Motion's (RIMM) BlackBerry and other smartphones offer the tantalizing prospect of growth in an otherwise sour retail market. The whiz-bang devices often combine voice communication with Web browsing music players and digital cameras. Better yet smartphones generate solid profit margins. Best Buy's new stores offer about 90 different phones and service from 9 separate wireless carriers. ...