If you have a iPhone or iPod you should look into iTunes match. It is 25 bucks a year (2 bucks a month). It will scan your library and if the itunes store has the songs you have in the store it will add it without uploading. It will upload the stuff store doesn’t have. I have around 12000 songs in my library and it matched about 9000 of the songs so it only uploaded about 3000 songs.
From there it lets you just stream your music from Apple’s servers when you are on the go.
And in the event of a hard drive failure you can just download all your music again. I mainly use it for a back-up of my music. And when you download the music it comes back down as a 256K AAC file. I ripped all my CD’s as 128K back in 2001 when I had a 20 Gig hard drive. So it was a way to upgrade most of my music.
http://www.apple.com/itunes/itunes-match/