If you want to keep up with what's happening in the GPS world (or need advice on what type of a unit to select), I recommend three Web resources. GPSInformation.net is one of the oldest GPS sites on the Net, and provides reviews, firmware update news and general information. GPS Passion is a European site that features GPS news, reviews and discussion forums. NaviGadget is a blog that provides extensive coverage of the latest GPS devices to hit the market.
Each of these sites provides unique information, so if you're interested in GPS, be sure to give all of them a quick look.