FLAC is particularly useful for transferring audio over the Internet. There are a few pocket audio players which can handle FLAC. FLAC is a lossless codec. By definition the reconstructed audio from an FLAC file should be identical to that from which it was derived.

I don't use FLAC unless I'm providing for someone who may need it, or happen to be working on my PC, but use ALACs (Apple Lossless Files, a close equivalent) regularly, Andy (mainly because the Mac-based programme I use for time shifting produces them), with great success. They share the .m4a container with AACs (Apple Lossy Files), so they'll open directly in iTunes for those who use it, and they convert to wave files easily and impressively when needed. I've steered well clear of mp3s right from the start, except as a basic travelling back-up, (probably because I've spent too long in Hifi circles and I don't like the way their compression affects the sound, particularly the low-level detail which recreates ambient nuances) but the Lossless route certainly works for me.

Much of the signal space on a CD is taken up with the complex Reed-Solomon error correction code, which duplicates the material so that a mechanical player has two chances to retrieve and interpret it: there's really no need for it to be there if you're storing it as data and playing back from a solid-state reservoir, so you really aren't compressing the signal itself at all in either Lossless format given the same 16/44.1 standard, even though it's taking up less space: one might even describe it as a win/win situation. 

On the Mac platform, it's easy - there's a little bit of Freeware called Tool Player. For PC, one of these should help.

In the fountain of this forum's knowledge, I am but a sprinkle, JP_V.