It was going the same for me. This was after placing the phone on DFU mode during the upgrade process and restarting the phone several times. What really helped was after doing a full backup, clicking on the Restore button in iTunes. Plan on taking up about 1+ hours depending on the number and size of installed applications. After that, I notice it start slowing down after certain apps fail and taking me back to the SpringBoard. A reset brings it back.

This won't make your phone as responsive as a 3Gs or when it had 3.1 code, but it worked better for me. Unfortunately, moving to 4.0 code is necessary to get security updates for iOS. YMMV and all that but hope this helps.

It's definitely a window into history. 10 years ago you could use ordinary batteries in your cell phones. You don't see these ads anymore.

LIFE did it through Google Books also. They have it from 1936 to 1972. Check out the one they did on Apollo 11.

You need to elevate the privilege of your editor. If you're using Notepad, right-click and select "Run as administrator". It now has the rights to edit and save the Hosts file.

What's interesting is that under this elevated privilege, you won't be able to drag-and-drop a file from lower privilege level processes (e.g. Windows Explorer).