Part of the Google I/O onslaught yesterday was an update to Google Play Books for both Android and iOS. In and of itself it's not exactly ground-breaking, but Google'll now let you read books uploaded to your Google Drive (through Google Books), which means cloud-syncing for your own, erm, acquired books.
There's no getting away from it -- book piracy is rampant for those with ereaders and tablets. But one thing that's been lacking is the ability to sync your non-store-bought books between devices. Google Books now does this for epubs and PDFs. Pirates delight, as well as everyone else who doesn't want to be tied to Amazon, Kobo, Barnes and Noble or the rest. [Google Play, iTunes]