One thing which must, must, MUST be remedied is eBooks on the iPhone. I was thinking of creating some sort of WebKit interface (as soon as I learned WebKit, anyway) to allow one to convert Gutenberg text files to a more iPhone-friendly interface on-the-fly. Well, as it turns out I don't have to, because some other people have gotten there first.
For instance, visit manybooks.net, which has hundreds of texts from Gutenberg already available in an iPhone friendly HTML format, as well as small PDF files. The HTML implementation is a little wonky at the moment, but I assume it will get better with time.
The other alternative is textoniphone.com, which looks promising according to a brief review in iPhone Dispatch. Alas, I can't evaluate it myself, as they'll be upgrading their servers all weekend.
edit: Matthew (that's Mr. Manybooks himself!) mentions in comments scrollbox.org, another alternative which looks very promising. Personally, with the creation of the unoffical iPhone SDK, I believe the best solution would be a custom-made app based on GutenMark. But my ideas have always been bigger than my coding ability...