iPhone and lack of local user storage

In my ongoing internal struggle to decide if an iPhone is for me or not I started looking around last night for articles on how to use it as an ebook reader. I’d like to do this and I’m sure some enterprising individual is going to come up with a solution that will work great with things from Project Gutenburg and pdf’s and hopefully iSilo and other formats that have been around for ages.
I found a few good solutions for online books, like Open Library‘s online reader, and you could maintain your page by keeping a safari instance on your phone open to the site on the last page you read, and also use the squeeze to zoom the page in safari. This is not to terrible considering all of the ebooks should be pretty slim downloads and a real ebook reader will probably implement some way to store the books in the local sandboxed sql storage each application can access.
This made me realize that it would be difficult to take a pdf from an email attachment and save it then open it in an ebook reader because as far as I know the iPhone has no traditional local shared storage among applications. I see this as a pretty big shortcoming right now. The iPhone is terribly powerful yet severely crippled it seems as I dig more into what I would have to sacrifice by changing over to one.
Lets take the following scenario for instance. My wife emails me a great picture of our daughter she took on her phone, I want to save that and open it in my favorite image manipulation program from the application store, as far as I know there’s no way to do this right now. Each application is sandboxed in it’s own area with it’s own non shared storage. I open images and mp3′s in several different user written applications on my windows mobile phone pretty often. An operation I do pretty often is take an image with the built in camera, save it to the SD card, open it in ceTwit to post the image to TwitPic, then upload it to flickr or possibly mail it off to someone else.
More to think about in my pondering of the iPhone, someone enlighten me if I have this wrong but I couldn’t find any information that was counter to this thinking.
Sure I could get around this all by jailbreaking a current iPhone 1 but I don’t want to do that. I want to use the device as it is and I want Apple to empower the user to use the device to it’s full potential.