Apple today released the fourth iOS 5 beta version to members of their iOS developers program. This version build is listed as Build 9A5274D. In this build Apple enabled the over-the-air-update feature for those running iOS beta 3, so you can wireless and directly update your device if you’re in iOS 4 beta 3.
You can also download iOS 5 Beta 4 from your Apple developer account. If you’re not a developer, you can google the IPSW, download it, and get a developer to register your UDID. And remember, if you are using GEVEY SIM to unlock your iPhone wait until someone confirm Apple hasn’t block it in this update like they did in the previous iOS 5 beta.