That's a really good idea to match the iPad's resolution, but you lost me with the last part...if 1024 is the longest dimension of the iPad, then why would 600 be too large?
Ultimately I want to use the iPad to showcase my photos. So that's where the 1024 figure came from.
On the other hand I also want a web page with a gallery site. By the time you add thumbnails, info areas, keywords, etc. 600 pixels was just a bit too big. You can take a look at the work in progress if you would like:
http://photography.jeffknox.com/ios3.html
Keep in mind that this is only a couple of days worth of work so it is very rough. The images are capped at 500px but you are able to tap on an image to get a larger view. (That part isn't uploaded to the server yet.) The tab pannel to the right hand side can be navigated by swiping left/right or by tapping on the arrows in the header. The thumbnails can be drug left and right to scroll, tap to select.
I did consider larger images where tapping on the image would bring up the controls but decided I wanted the info and image to be display together as you browsed the thumbnails. Currently the thumbnails are shown three times just so I can test the scrolling. I think I have a solution for navigating the galleries so that will come in the next few days.
This has grown out of a
Flash implementation that has more functionality at the moment but obviously no iOS support. A lot has gone into the backend and I'm happy with how quickly it is translating to and HTML/CSS solution. I haven't added the CSS to adjust for portrait mode. I wanted to nail down the design elements before I did the portrait modifications.
I'm also able to post individual images on forums like the Photo of the Day here. Those will often be shown at the full 1024px.
So probably way more than you wanted to know, but there you have it: Why 600 pixels is too big.
Edit: Oh and some of the features will only work on a newer browser such as those based on WebKit due to some of the CSS3. So don't bother trying it on IE6.
