I have a carrying case that contains nothing but CD-R's in my car, probably about a hundred of them.
I keep all my store bought CD's (somewhere just over 500 of them) in their cases, but I don't have cases for my CD-R's, so I generally keep them all in one big carrying case.
Most of the CD's are mix CD's of my favorite songs from the above mentioned store bought albums. Yes, there are downloaded songs on these albums, too, although I've never downloaded an entire album (I will make an exception when the new Metallica album comes out, just out of my own principles).
Some of the downloaded songs are rare b-sides that are hard to find elsewhere. I have two albums full of John Bush-era Thrax b-sides. Of these, I'd say that I actually own the albums or singles that these are from for about 2/3, and have downloaded the rest because I couldn't find those albums anywhere. (I challenge any of you to find me an original CD containing Bud E. Luvbomb's Satan Lounge Band)
Some are by artists I've never heard before, but wanted to check out. Radio stations in my area never play the type of music I'm interested in, so how else am I supposed to get exposed to the artists. I'm not going to buy them on blind faith alone. Prior to CD's, I commonly copied entire albums borrowed from friends onto a blank tape in order to check them out. How is this different?
Other songs are songs that I previously owned on tape, but didn't want to have to buy the whole CD for one or two songs. I've never downloaded an entire album that I've previously owned on tape...if I liked the tape enough to want all or most of the songs on CD, I've just bought the CD.
Some songs I've never owned, again basically because I didn't think it was worth it to pay $15-20 to buy an entire album just for one song. I'm not taking away from record sales there, because if I couldn't download it, I wouldn't have bought the album anyway. I just never would have bothered.
So you can agree with my logic or not, but I'm not going to apologize for a carrying case full of burned CD's. I will apologize, however, for having such a long-winded post