The idea is to create an informal points system in Moodle that represents “Moodle Bucks”. Basically a bank account for student users so that they can accumulate (and perhaps spend) bonus/special points through the Moodle system.
Back in 5th grade we did the same with paper and stickers. Students got a sticker (or more) for helping out a fellow student, getting a high grade on an assessment or for many other academic and non-academic reasons. At the end of the year we had an in class auction (using the stickers accumulated) to buy toys and little treats from the teacher.
Would Moodle Bucks be a good addition to your Moodle? Let us know and visit the forum to weigh in: http://moodle.org/mod/forum/discuss.php?d=144963