Listening to Kathy Sierra's etech speech about neuroplasticity, I paused it as Sierra mentioned the breakthrough where researchers realized that dull environments inhibit learning. Thinking of my idiosyncratically hyper-clean office as a mental cage (I still think of it as dropping all other concerns allowing me to focus on work), perhaps rotating diverse items through my life would be more fun.
So, how about the following? Take something interesting from your life and give it to someone else with the injunction that in one week's time, they have to pass it on to someone else. This hopefully keeps cool things cycling through your life as people feel indebted when you give something to them, so you should get something back; otherwise, give a cooler gift next time ;).
A slick add-on to this would be a mapping site to track the goods given. Total gifts in flight would be cool, especially time-lapsed over a map. If this works....
As they say: T'is the season for giving ;)