The Kindle 2 is an updated version of the original Kindle by Amazon. It's a wireless e-book reader that downloads books via an EVDO/CDMA network. It has 2GB of memory (and an SD slot). Beside books the Kindle also supports many newspapers and can access Wikipedia.
The E Ink display has been upgraded to 16-levels of gray (from 4). It is available now for 259$. There's also an international version - which allows global wireless. It costs 279$, and each non-US download costs 1.99$.