Developer/musician Paul Barrett (aka echodeck) has created pop.ularity a nifty web-based music quiz based on last.fm and the Echo Nest APIs.  In the quiz you try to guess which band is hotter on the web. The quiz uses Last.fm plays, Last.fm listeners, Echo Nest Hottttnesss and Echo Nest familiarity to measure popularity for each band.

It’s a fun game – give it a whirl!     http://pop.ularity.co.uk/