In short, WAAS approach-capable GPS units provide lateral and vertical guidance to many airports that have never had a precision approach. As of Feb. 2007, there are 640 GPS-based LPV approaches with minimums as low as 200 feet and 1/2 mile visibility. There are also over 1000 LNAV/VNAV approaches that provide vertical guidance with WAAS capable GPS units. There are also 1000s of other approaches with advisory vertical guidance. More and more approaches are being added each month.