cel4145
Headphoneus Supremus
You might have one that works, but you can get a Sansa Clip for so short money that spending hours converting your stuff might not be worth it.
I use Media Monkey (and I'm sure other players can do this too). No effort. You can setup a sync profile so that it automatically rips to mp3 from flac. Sure, it would take a while the first, but you don't need to babysit. Just leave it running.
I can also heartily recommend the Sansa Clips. You can usually catch one for $30. For instance, http://www.amazon.com/SanDisk-Full-Color-MicroSDHC-Stopwatch--SDMX22-004G-A57R/dp/B005FVNGRI/