Amazon MP3 saved me a modest amount of money
Just bought my first track from Amazonmp3.com. Finally they have song previews that I can play in Firefox on my iMac. For the longest time the tracks were Windows media files [or something else non OS-X-friendly]. 
Looks like they moved to Flash or something.
P.S. If it’s not Flash, I apologize in advance. Some irrationally irate commenter on my blog post about Amazon Unbox (from 2 years ago!) had a tizzy when I mistakenly said Unbox was a Flash app. >:(
