There are various programs that support flac decoding. I use cdex with flac as an external encoder/decoder. cdex is very powerful, so you effectively get to skip a step as in RLG's method (but really, under the hood, the same is happening .. it reads the file in as a wav file and passes it to your external encoder using the command line options you specify, it's just easier this way since it's all done in a single "job".)

You can get flac plugins for winamp and other players, so you can play them natively using your favorite player.

Then I use dbpowereamp for converting from flac to anything else. dbpoweramp is a very handy program.

-David