My iTunes is giving me this error message when I try and sync my iPhone?

"The iPhone "RJs iPhone" can't be synced because there's not enough free space to hold all of the items in the iTunes library (additional 4.11 GB required). Even though on the bar it says I have about.47 GB free. I have an iPhone 4, 8 GB. What do I do to fix this?

On the Summary tab, check "Sync only checked… " And check the things you want to sync. Hope it helps!

If you have a lot of music in your library, check the box on the summary page to convert all songs into 128 kbps ACC format. Chances are your music will take half as much space like that. If that doesn't free up enough space you'll just have to pick and choose which apps and music to sync to the phone. For that, just go through the tabs: summary - apps - music etc and check the items you want loaded on the phone.