Munsey's blog has a post talking about Mobi support coming to the iphone (I think it was promised before the end of last year). They were talking about how cool it would be to read a few pages while you're stuck in a line and then coming home to read some more on your Kindle - with your page being synced. Could this be a use of the new "advance to last read position" that shows up in Kindle firmware 1.2? (I don't have 1.2 yet, so I'm paraphrasing).