Mekentosj.com has released an update to its popular Papers academic research app. Papers 1.8 adds support for PDF annotations and note-taking for iPad users and adds Fast App Switching support on multitasking-capable iOS 4 devices. The update also includes high-resolution artwork for the iPhone 4 and brings support for opening PDF files in Papers from other applications such as Mail and Safari on iOS 4. Additional improvements include the ability…