You may want to ask a lawyer for specifics but as far as I know this is the general rule.
If you have a legitimate copy of an album (CD/Tape/LP/etc.), you are entitled to make a copy of that for your own personal use, without breaking any laws whatsoever (or at least without fear of the RIAA breaking down your door). This copy can be in any format. ie. buy a CD and make a copy on tape, or as I do a lot of, buy vinyl and copy to a digital format.
Note: This does not allow you to the redistribute those songs to anyone and everyone as the pro Napster crowd seems to think it does.
you can make a "personal backup" of any music, video, games, etc. The only possible exception is where the origional media is copy protected. if you bypass the copy protection you could be infringing on the DCMA (i think it's the DCMA, at least).
but thats only a minor point and yet to be proved in court (see 2600 vs MPPA case)...
Just as a side note, it is NOT legal to make copies for friends if you're not making money off of it. I say this because I know someone was going to say you can. I work for a company that deals with copyright (specifically music), and so I can vouch that the two statements above are correct. Except that I'm not sure about breaking copy protection, either. My guess it that it would be illegal (for lack of a better term) since you're buying a license to use the software, not the actual software itself. Which is why not everything is open-source. As for music, I would think it'd be legal to break copy protection, as you're buying the actual music & CD.
Apple? Macintosh? What are these strange words you speak?