Lossless compression does not affect quality at all. If it somehow does, something is really wrong with your computer and/or the program used to play the files. It really is a storage-based compression, used to minimize disk space only. When you play such a file on your computer, the file will be decompressed to raw PCM before playback, in real time. So, both in theory and practice, playing back a losslessly compressed file or a WAV file is absolutely identical. There is no jitter involved here either, since when the data is fed to the soundcard/DAC it is already raw PCM in both cases. Jitter may happen from the buffer (in the case of a computer, this will be RAM) where the PCM is stored to the final destination of the data, the DAC. This applies to all compression methods, including MP3, Real Audio or whatever you can think of. At the time of playback, the data is raw PCM. But of course, for lossy compression methods, the damage is done when encoding the files, I'm just telling it as an example.
Saffy, there are several CD burning apps that will burn FLAC files directly to disc (it decompresses them automatically when burning), so there's no need to decompress them manually first. :) I use Roxio Toast on my Mac, but there are many others I'm sure. Nero works well in Windows for instance.
Kenl, if you want to decompress Apple Lossless, just use iTunes. The same argument as above applies though - there is no way a losslessly compressed file can sound different than a WAV file, unless something is seriously wrong with the application that plays it.
