Being able to overlay Doppler weather on your GPS is fantastic: Bushnell ONIX400CR GPS/XM Handheld - Orbitcast.com . I'm sure, though, it requires a subscription and I wouldn't use GPS out in the wild enough to justify it. But it's a great feature move in the world of GPS. Well, the GPS units and the hand-helds (like my Dell Axim 51v PocketPc) are beginning to merge.

If images can be served up with EXIF meta-data regarding the lat/long rectangle associated with the image, more live layering can be accomplished. E.g., if you could go to weather.live.com and be able to download to your device a meta-data'd Doppler image, it would be no problem for your current GPS app to overlay that on its current map.

Or whatever kind of map. Contour. Traffic. Fun-zones.

In the meantime, I'm certainly putting off buying a new Garmin GPS unit while innovations like this are happening. And if the Bushnell happens to have free Doppler radar images and image overlaying (and at least a SiRF III chipset), then it's mighty tempting to consider picking on up.