[phil]

I don't understand the hate in the comments. Two things:

1) The simplest applications are still hard to polish this much. In fact, simple things can often hide some of the hardest design choices.

2) Three years ago, Twitter apps were the UI design playground of choice. Now that they've told everyone not to write new clients, UI experimentation has shifted to other applications. Compare Cheddar to Clear, for example. Both are nominally to-do lists, both have carefully thought out custom interfaces, but they express very different philosophies about software design.