Google's desktop web site has been offering the text of public domain and other licensed books for a while, but they've just launched a mobile version as well, books.google.com/m . Ostensibly formatted for Android devices and the iPhone, it works after a fashion on S60 devices too, with their Webkit-based browsers. Some screenshots below to show how it works...

Here's the announcement by Google. And here are some screens of the mobile books site working on the Nokia 5800 XpressMusic:

There's artwork in places too, scanned in. As you can see the formatting and fonts aren't ideal for reading on the small screen, but doubtless Google will tweak this and make the mobile pages more compatible as time goes on....

Steve Litchfield