I really do no need to start writing, but just one more thing that came out of last Thursday's meetup. We talked a little about when some of the cool Snow Leopard features like Blocks and Grand Central Dispatch might be coming to the iPhone.
Again, I'm purely speculating, but I think we will see blocks sooner rather than later, maybe in iPhone SDK 3.5. Grand Central Dispatch is harder to predict. Although there is some value in it now, since the iPhone has two processors - a CPU and a GPU - the real power of GCD comes with even more processing cores, and I have no idea if or when we'll get a multi-core iPhone.
But, blocks? Blocks on the iPhone would be cool, and you know what? You don't have to wait.
Sure, by using this, you don't get block support in the Foundation and UIKit classes, but you do get blocks, and you can always create categories to add block-based methods to existing classes, so you might want to check it out.