Through this Enrique Dans' post I've come to this post where they talk about the new i-Phone application to replicate Kindle functionality.
As you can imagine I jumped into i-Tunes store to download it and... Shit! is not available in the spanish store... I'm now investigating how I connect to other stores :-(
Try this link to access the app from iTunes: http://click.linksynergy.com/fs-bin/stat?id=8fq8akZie*M&offerid=146261&type=3&subid=0&tmpid=1826&RD_PARM1=http%253A%252F%252Fitunes.apple.com%252FWebObjects%252FMZStore.woa%252Fwa%252FviewSoftware%253Fid%253D302584613%2526mt%253D8%2526partnerId%253D30