According to Engadet.com , the Government has thrown the switch on a new, more powerful, and accurate, GPS signal. This new GPS system will allow for better signals in urban areas, and possibly indoors, and will work in smaller devices, making possible for GPS on your cell phone. Our older GPS devices may be able to use the new signal if your device is upgradable. Check your manufacturer's website to see if their are updates for your device.
The GPS is one very cool piece of technology, and this new signal will hopefully provide a more reliable signal. I love using my device when I'm on training runs to track my mileage, and it's also useful when hiking and camping to keep your bearings, although I have to always remember to back extra batteries. Beside those uses, there is also the growing Geocaching craze.