Give a look at some forms of Euphorbia pulvinata.
Some forms pictured on that page have more prominent spines, others merely ridges and more persistent leaves very similar to your plant.
In particular, this one reminds me very much of your plant:
This message was edited Aug 20, 2012 4:00 PM
Hmm, did you get the message, Guzmania2010? I never heard anything back.