To access your PhotoZoom DeepZoom images in Seadragon on iPhone, go to the Add RSS Feed screen and type this Url (replacing craig with your PhotoZoom alias).
You can read more on the DeepZoomPublisher.com website, including downloading the c# code.
Here are the iPhone screens using this url http://deepzoompublisher.com/PhotoZoom/rss.aspx?user=eflaten (from the previous post)
UPDATE: Seadragon seems to CRASH sometimes when accessing some RSS feeds. I think it is fixed now -- and was related to either (or all of) the following:
<description> tag containing linebreaks (must be all on a single line - fixed in generated RSS)
<link> tag being too long or containing unexpected characters (fixed in generated RSS)
<author> tag not appearing EXACTLY in the format
user@domain (fullname) (I've put a fake email address in the generated RSS to 'fix')
Guid not being a 'real' GUID (instructions say it doesn't have to be, but maybe it does...)
Drop a comment if you experience problems with it.