Apple has released iBooks 1.5 for iOS devices which adds the following new features as well as some stability and performance improvements:
• Nighttime reading theme makes reading books in the dark easier on the eyes.
• Full-screen layout lets you focus on the words without distraction.
• iBooks now features an improved selection of fonts, including Athelas, Charter, Iowan, and Seravek.
• Beautiful new classic covers for public domain books.
• A redesigned annotation palette makes it easier to choose a color for your highlighted text.
iBooks 1.5 (free) is compatible with iPhone, iPod touch, and iPad and requires iOS 4.2 or later.
More info and download link via Apple’s iTunes App Store (20.7MB) here.