I don't remember how i did it, or if it was already enabled, but with 11.04 i had the ability to hover over an mp3 file on my computer and it would start playing. I guess it was like a preview thing. I could literally listen to the entire song without clicking it as long as i held my mouse over it. As soon as i moved my mouse off of it, it would stop playing.

Now, on 11.10 i don't have that anymore. I never realized how useful it was until it's gone. Does anyone know how to re-enable that feature on Oneiric Ocelot?