Incentives and rewards in the bush?

I used to bring with me a few small treasures and new books as rewards or incentives, but usually i ran out of these things in a very short time!  What to do when you don't have shops that sell nice things or even have a reliable post office to order things from?  Well, you get creative, of course!  Here are a few ideas that I came up with.....

I wanted my boys to memorize all the countries, by continent, with their capitols as well as other things like Bible books, planets, etc.  As an example, for each continent mastered, i made a small card with a prize on.  For North America they could earn 45 min on a favourite computor game or $5 to be spent on a kindle book (via internet)
For South America it was an hour horse riding as i knew we were going to a place where that was available. 
There are many things that can help them to work on something hard - small amounts of money to save up for a furlough, a special picnic, a chocolate, or whatever will motivate your kids - it doesn't always have to be big and grand, just something that will inspire a bit!

Bella