Amazon is today adding BlackBerrys to its stable of Kindle-compatible devices and also taking the opportunity to remind us that it's working hard on Mac and iPad versions of its software. The app is a freebie download for Americans (sadly it's not international just yet) and should offer the same functionality as its PC and iPhone brethren -- namely automatic syncing via Whispersync and what Amazon hopes will be a seamless reading experience from one device to the next. There's also an in-app book store, as well as the ability to create bookmarks and view annotations from other portable Kindle readers. Go download it at the Amazon link if you care, or move right along if you don't.