That was a bit odd. My iPhone 3G started acting a bit weird so I turned it off. I turned it back on, and it took what seemed like forever to start back up.
When it eventually did come back, it was deactivated! It had the connect-to-itunes image (not text like the image above) at the top of the screen, no service name in the top-left corner, a “slide for emergency” thing at the bottom and an info button which showed the ICC ID and IMEI.
In a bit of a panic I turned it off and on again.
It took another eternity to start back up.
And then it booted normally, with the “iPhone is activated” message. Is my iPhone dying, or is it just time for a factory restore in iTunes?