We’re not sure who’s buying this computer add-on over a traditional GPS system, but Microsoft’s 2007 edition of Streets & Trips was just released. For $129 — about $300 less than most standalone GPS systems — you get software and a peripheral that plugs into a USB port then acts like a standard GPS unit. Yes, that means you need your laptop on your passenger seat while driving. Microsoft says its software is more advanced than what’s used in standalone systems, but unless you’re constantly driving with your laptop (and who does this? Salesmen? Contractors?), Streets & Trips 2007 seems too inconvenient for the money you save over other GPS units.