iOS 4 is OUT! You can upgrade in iTunes, or via manual download from the links below. Then, you can install the new software in iTunes by holding the Alt/Option key (for Mac users) or Shift key (for Windows users) while pressing the "Check for Update" button in iTunes, and selecting the downloaded IPSW from your drive.
I recommend downloading it while it's hot, since Apple's servers will quickly get overloaded with users trying to get the new software.
Direct IPSW Download Links:
iPod touch 2G: http://appldnld.apple.com.edgesuite...20100621.tr49t/iPod2,1_4.0_8A293_Restore.ipsw
iPod touch 3G: http://appldnld.apple.com.edgesuite...20100621.AzSP9/iPod3,1_4.0_8A293_Restore.ipsw
iPhone 3G: http://appldnld.apple.com.edgesuite...100621.58Yt4/iPhone1,2_4.0_8A293_Restore.ipsw
iPhone 3Gs: http://appldnld.apple.com.edgesuite...100621.5urG8/iPhone2,1_4.0_8A293_Restore.ipsw
iPhone 4: http://appldnld.apple.com.edgesuite...100621,Vfgb5/iPhone3,1_4.0_8A293_Restore.ipsw
I recommend downloading it while it's hot, since Apple's servers will quickly get overloaded with users trying to get the new software.
Direct IPSW Download Links:
iPod touch 2G: http://appldnld.apple.com.edgesuite...20100621.tr49t/iPod2,1_4.0_8A293_Restore.ipsw
iPod touch 3G: http://appldnld.apple.com.edgesuite...20100621.AzSP9/iPod3,1_4.0_8A293_Restore.ipsw
iPhone 3G: http://appldnld.apple.com.edgesuite...100621.58Yt4/iPhone1,2_4.0_8A293_Restore.ipsw
iPhone 3Gs: http://appldnld.apple.com.edgesuite...100621.5urG8/iPhone2,1_4.0_8A293_Restore.ipsw
iPhone 4: http://appldnld.apple.com.edgesuite...100621,Vfgb5/iPhone3,1_4.0_8A293_Restore.ipsw