Or you can show self restraint and not download every single song you've ever heard, ever. I'm only going to put song I really really really want to listen to on my phone. Remember, its just a phone.
Sure, Ill take some videos of my gf or kitty, but Ill just save them to my computer, then free some space. Sure Ill put some podcasts on there, but when im done ill take them off and free some space. This song is great! This song is wearing on my nerves. Ill take it off and free some space.
Not every kb of digital enterainment you own needs to go on your phone.