iPhone 3.0 is NICE. We've got a huge gallery below, as well as impressions of how it runs. Spoiler: it runs well, even if it's a beta development build.
• Note syncing is pretty great, even if it is almost two years late
• You can sync notes through MobileMe as well as through iTunes
• Your call list now shows the location the call came from (was hidden inside each call screen before)
• Spotlight is great and speedy unless you have nine pages of apps, then it's SLOW
• MMS is currently broken (Could be because of AT&T plan, not because of the software - Thanks commenter!)
• There's a new MobileMe locator option to locate your phone from MobileMe. This is possibly so you can see where you left your phone, or maybe even where the thief who stole your phone is? Not sure.
• SMS has subjects now
• The call log is improved
• The new lock screen shows artist/track/album info. Sweet.
• Widescreen SMS works pretty well.
• Overall 3.0 is slightly more sluggish (because it's beta) than 2.2.1.
• You can search from almost any screen inside the iPod app
• Tapping the home button once from the home screen brings up the search screen
• When minimizing apps and going back to the home screen, the animation kinda fades out now instead of just disappearing into a speck
• Searching is fast, but it's not instantaneous
• You CANNOT select and copy text from Word documents
More notes to come - Thanks to everyone who helped out!