Just a quick post to warm people that the iOS 4.0 upgrade will significantly slow down an iPhone 3G. I don’t know if it’s the slower processor or the lack of RAM, but I very much regret making the upgrade. The only useful features of iOS 4 that are enabled on the 3G are folders and the new version of Mail. While those are nice, they don’t begin to make up for the incredibly slowness of the update for certain tasks. Typing in addresses in Mail, for example, often hangs the phone for several seconds. It now takes a few seconds for the settings menu to first come up, as well.