REI offers the Spot Trace GPS Tracker for $49.89. Pad your order over $50 (these gummi bears cost $2) to bag free shipping; otherwise, shipping adds $5.99. (In-store pickup is also available. Cabela's and Fry's Electronics have it for a few cents more.) That's tied with our mention from a year ago and the lowest price we could find now by $49, minus the cost of padding. This waterproof tracker features motion-activated tracking, which uses vibration sensors to send GPS coordinates only when it's moving. It includes four AAA rechargeable lithium batteries.

This device requires a service plan for operation, starting at $99.99/year.