I've posted before about my tendency go through brief but intense phases where I listen to the same song over and over and over again. I'm currently doing this with Amy Winehouse's "Rehab." I think I find there to be something recursively pleasing about addictively listening to a song about addiction.
BTW, as a shout of to fans of replicators everywhere, it's National DNA Day today. (And, for our antipodal friends, it's also ANZAC day.) Cambridge is having this science festival for which they advertised a special 2-mile genome walk, but as far as I can tell it's just these red and blue gene-ly banners with chromosome numbers hanging from lightposts at intervals between Kendall and Harvard square.