Climbing Mt. Everest? The accelerometer in this rescue beacon detects the subtle movements that indicate you're still breathing, and the device radios your health status and location to rescuers. $400; mammutusa.com
Interchangeable soles offer the best grip for your terrain, whether it's rubber lugs for streamside hikes or felt for slippery boulders. Just snap one of six soles (two included) onto tongue-and-groove locks on the shoe's underside. A lacing system borrowed from snowboard boots lets you dial in a snug fit. $160; korkers.com
Postage prices just went up again (groan). Save yourself some change by using this DIY device to find out exactly how many stamps to slap on to that overstuffed envelope