Some good apps are AroundMe, FreeWifi, Pictorial, VoxerWalkie-Talkie, etc.
There are 15,000 Applications!
I can recommend Air Photo. It only costs 2 bucks. I've been using it for a couple of weeks with no problems. There's an informative article here which reviews it along with 2 other apps for printing from the iPhone: http://www.cartridgesave.co.uk/news/top-iphone-wireless-printing-applications/
Almost all of the applications on the iTunes store is compatible with the iPhone 4. Exceptions are applications which are for the iPad.
Yes.
Two of the highest seeling iPhone applications include Text Lingo and Angry Birds. See 'related links' below.
iPhone applications are individual applications that do different things. Developers from across the world design and implement applications to do things like edit pictures, connect with friends, etc. The majority of applications are games, whereas others are utilities. See 'related links' below.
balls
No
Both YouTube and Truveo have dedicated iPhone video applications.
Using iTunes, you can store songs, movies, applications, games, podcasts, and photos on an iPhone.
Yes, iPhone from Apple. It's just got more applications added onto it!
Yes! Apple hit it out of the park with the iPhone, anyone with a brain would recommend this!