I use my windows mobile phone for this. But, if you want something cheap and easy I have a spare device you could have for fairly cheap.

It an iblue 757 solar gps bluetooth data logger. It will track where ya go, is rechargeable and has a small solar panel thing to help charge on the go if you like as well. If you want to see its stats just bang that model into ebay and you will see specs and going prices.

Id take 30USD for it. It just sits in a drawer so what the hey.

cheers...