Following on the heels of the iTunes 9.2.1 update that was released yesterday, Apple has updated the iBooks app to version 1.1.1, which includes "substantial performance improvements when reading PDFs." While the new version of iBooks still lacks some lovin' for PDFs that e-books get (in-text Dictionary lookup, notes, etc.), this version makes swiping through PDFs smoother than before. Other improvements to iBooks 1.1.1 include:
• The ability to double-tap an image within a book in order to view it in greater detail.
• The ability to experience books that include audio and video.
• Look up definitions to English words inside books without a specified language.
• An answer to an issue that may have caused some book downloads to not complete.
• The addition of many stability and performance improvements.
The free update for both the iPad and iPhone/iPod touch apps is available now in the App Store.