Interesting idea. I included an activity report page in the SWF Activity Module (http://code.google.com/p/swf-activity-module/) that gives a graphic display of grades, time spent, number of attempts, along with feedback comments and thumbnails of any saved images (e.g. from Concept Map and Avatar Camera apps). It's designed to give a quick and easy way for learners to check how they've been doing on SWF activities, see where they're doing well and where they should spend more time.
Setting up some kind of side block that generates reports on learners' quiz attempts and awards badges should be fairly simple and easy to do. Probably, the most time consuming part of it would be deciding on how you'd like it to look and behave.