Backpack is finally live and available to the public. I’ve already signed up for my free account. As I suspected it is quite a nice web-based PIM (personal information manager) that works quite well with email (both sending and receiving) and sends reminders to your mobile. Though as Russ has pointed out it’s not quite as useful as it could be for mobiles. Still I think that the AJAX interface is quite slick and it really shows off the power of building web-apps with Rails.