I attended two conventions during January that convinced me that my love affair with the Macintosh is not unique. The first convention, Macworld Expo in San Francisco, was packed with 60,000 attendees trying to find out what's hot and what's not. Macworld Report One program that is definitely new and hot is Microsoft's latest release of Excel for the Mac. By now you must know that I consider owning Excel a must. In fact, if you only own one application, make it a spreadsheet — either Excel, WingZ, Full Impact, or Mac Calc. Excel 3.0, the new version, has added an icon-based tool bar at the top of the spreadsheet. The most useful tool for contractors will be an improvement to