.flacformat. While they play well enough on Totem and Rhythmbox, they won't on my iPod Touch (more on my love-hate relationship with the iPod Touch next time.) I had to find a way to convert them to a compatible format. A few quick searches on Google turned up
Really, there's not a whole lot to write about soundconverter. It does what its name says it does. You just specify the files you want to convert, and hit the convert button. Of course, before you do that, you might want to set up the preferences so you can specify the format you want.