If you have an iPhone or iPad then check out TrackMyTour (I'm the creator of this app). It's not a real time tracker so battery drain isn't a concern. It also lets you queue points offline when no network is available to submit later when you're back online. Here's a sample map from my tour last summer: http://trackmytour.com/g68Px.
I will have my iPad with me and plan to keep a log each day. I will download your app and keep you updated. Thanks