Although Amazon.com's new Kindle 2 ebook reader is garnering most of the headlines in the ebook world at the moment, I think a pair of mobile-related announcements from Google and Safari Books Online may make more of a difference for the future of ebook reading.

Google Book Search -- Last week, Google announced a mobile version of Google Book Search, which gives you access to 1.5 million public domain books in the United States (and 500,000 in other countries) from your iPhone, Android-based phone, or other Web-enabled mobile phone.

The only new piece here is the mobile-optimized versions of the books, which required that Google use optical character recognition to extract the text from the page images made by scanning physical books. Needless to say, there are plenty of recognition errors, but you can tap on any paragraph to see the image of the original.

Although the normal version of Google Book Search offers limited previews of in-copyright books, along with purchase links, preview-only books aren't yet included in the mobile version of Google Book Search. I imagine it's only a matter of time before that changes.

Of course, the mobile version of Google Book Search works only when you're online, rendering it less useful than an actual iPhone app that would let you read when you're on a plane, unable to pick up 3G wireless data service, or using an iPod touch out of range of a Wi-Fi network. For that, one of the ebook apps in the App Store would be better. I wouldn't be surprised to see either Google or another company figuring out how to make books from Google Book Search available offline in the future as well.

To visit Google Book Search from your iPhone or iPod touch, go to http://books.google.com/m.

Safari Books Online -- Coinciding with O'Reilly's Tools of Change for Publishing conference, Safari Books Online announced a beta version of the subscription-based library service. With Safari Books Online, you (or more commonly, your organization) pay a subscription fee that gives you access to thousands of technical books from O'Reilly, Peachpit Press, Prentice-Hall, Microsoft Press, lynda.com, and others. And - full disclosure here - although they're not quite all available yet, we're working with O'Reilly to add our current Take Control ebooks to Safari Books Online as well.

If you have a Safari Books Online account, point your iPhone to http://m.safaribooksonline.com to login and see how it works. It will launch officially on 23-Feb-09, so there may be quirks until then. As with Google Book Search, the mobile version of Safari Books Online requires that you be online.

Amazon Ebooks on the iPhone? Although the specifics aren't yet clear, Amazon has started to talk about making their 230,000 ebook titles available on mobile devices other than the Kindle. In the Kindle 2 press release, there's the following ambiguous quote: "Kindle 2 will also sync with a range of mobile devices in the future."

Plus, last week, Amazon spokesman Drew Herdener told the New York Times, "We are excited to make Kindle books available on a range of mobile phones. We are working on that now."

It's hard to imagine exactly how all this would work, given some of the technical limitations. First, Amazon's Whispernet system uses the Sprint network - does that imply that only Sprint-compatible mobile phones would be supported? I can't see Amazon negotiating 3G data service plans with every carrier out there when they haven't even been able to make the Kindle available outside the United States. That points instead to Amazon allowing connections over the Internet, but that would then cause potentially large charges for mobile phone subscribers who don't have unlimited data plans.

And then there's the question of DRM. Decoding DRM protection requires special software, which Amazon would have to write for multiple mobile phone platforms - iPhone, Windows Mobile, Symbian, etc. That's not inconceivable, but it seems like a lot of work, and potentially a tricky distribution issue for devices other than the iPhone and iPod touch.

Finally, although it's easy to imagine a decent iPhone app for downloading and reading Kindle ebooks from Amazon's Web site, Apple's SDK agreement restricts applications from providing access to other online stores without permission. Apple tends to do things that benefit Apple, so I could see Apple withholding that permission unless Amazon coughed up a percentage of sales made through its iPhone app.

"Without Apple's prior written approval, an Application may not provide, unlock or enable additional features or functionality through distribution mechanisms other than the App Store."

In short, although none of these issues are insurmountable, there are many technical and contractual stumbling blocks that could prevent Kindle ebooks from appearing on the iPhone and iPod touch any time soon. I certainly hope I'm wrong, but I'm not holding my breath.