The steps of adding a framework in Xcode 4:
1. Click current project in Project navigator.
2. Click a target in Project editor.
3. Choose Build Phases tab.
4. Expand Link Binary With Libraries
5. Click + button, add a framework.
6. Go back to Project navigator. You will see the new framework added. You can drag it into Framework group. If you have more than one target, you need not repeat the steps for other target. Just choose this framework in Project navigator, and make selection in Target Membership in File Inspector on the right Utility window of Xcode.