We have talked a bit at the office about carrying personal locator beacons (such as SPOT, ACR, McMurdo). When we were doing research on them, one thing that we did find is that the quality can vary. So any of you shopping for one may want to look at a few consumer reviews first.
That aside, anyone that is going out hiking or camping, especially in more remote regions, should think about getting one. Some outdoor supply stores even rent them.