Can someone suggest a good personal gps unit for hiking and kayaking?

[skisonone]

I am looking for a personal gps unit for hiking and kayaking. I saw one not too long ago that works very very simply. You turn it on and mark your position when starting out and it tells you how to get back. That's all it does. It is meant to be worn on a jacket zipper or a lanyard. Can someone tall me where to find it or suggest something else? Thanks in advance.