Ok well you may have found this already but there is a Japanese app called iComic (or iphonecomic) which is available via googlecode http://code.google.com/p/iphonecomic/.
It's only available in Japanese (or Korean) so far.
Also, I get the impression it only handles .zip files and not .cbr or similar.
I haven't used it (yet) myself so can't give an opinion.
Does anyone know if this app comes up on any of the sources/repos and if so which one/s?
Thanks for the source, that's great.
(...Hmmm I have so many sources now, I really need to figure out how to back them up... take ages to enter them all again...)
UPDATE: For those Japanese-/Korean-impaired users there is an English menu patch thingy here http://www.iphoneskinning.com/2007/12/iphone-comic-reader.html
What is the best source for downloading the comics?
Ok so I'm reviving a dead thread, but thought you guys would want this.
http://www.penjuinlabs.com/blog/?p=21
It's called jComix. It's in English and works great. It's a bit of a pain to transfer your CBR files, but besides that it's great.
Ok, Ok, guys, you all wanted a decent comic book reader. I, Philip Orr and Paul Holden, Judge Dread, 89ers, amongst others have put this together.
http://www.infuriouscomics.com/
The original blog post from my website can be found here.
http://www.bluepilotsoftware.com/blog/
The Murderdrome comic has been submitted to the AppStore for review.
Philip