http://www.insta-mapper.com

I used to use this until it was withdrawn, it's just been rereleased. Usual disclaimers re battery life & signal out in the sticks apply.

Was considering a Spot, but Im thinking this would keep the Mrs a little happier
She does like to knnow where I am occasionallly :)

I have used One Touch Location : http://onetouchlocation.creativeworkline.com/

and it does the job, not going to use it tomorrow as it relies on phone signal and that's pretty unlikely to have for most of the time.