O’Reilly publication on iPhone App Store
If you are interested in eBooks and don't mind them being non-portable, you can look at the growing items from O'Reilly on iPhone App Store. Just search for "oreilly" on iTunes and you'll find over 130 eBooks. By non-portable I mean you can only read it on iPhone / iPod touch and you cannot transfer it on your computer or any other device. The prices are mostly $5 that make them a good deal compared to the average of $40 in print format. Some good titles are Learning WCF and Myths of Innovation.
I found it when I was browsing O'Reilly's web site to purchase "RESTful .NET" eBook which is available for $10 (compared to $40 in print format). Unfortunately RESTful .NET is not available on App Store but at least I could get it directly from O'Reilly in 3 non-DRM formats: mobi, PDF and ePub.
I hope more publishers will join O'Reilly to publish their books on App Store. I searched for Manning, Apress, InformIT but didn't find them there. Am I missing any publisher of technical books on iPhone App Store? Let me know.