How To Speed Up iOS4 On Your iPhone 3G Or 3GS
If your iPhone 3G or 3GS has been running slow since the iOS4 update, this one modification has made a dramatic difference in how quickly my iPhone responds. This should tide you over until Apple figures out what the issue is.
1) Go to Settings > General
2) Click “Spotlight Search”
3) Uncheck everything
Finally, reboot your phone by holding the Home and Sleep/Wake buttons until the Apple logo comes on the screen.


