We're less than 24 hours out now from this years highly anticipated WWDC keynote, and we're continuing our look back on past events today with the 2011 presentation from Moscone West. Continuing the tradition of the previous 3 years, 2011 saw, the unveiling of iOS 5, OS X 10.7 Lion, and iCloud. This was also of course, the final keynote starring the late Steve Jobs.

iOS 5 continued the tradition of yearly updates to Apple's mobile OS. Headline features included iMessage, the iOS to iOS instant messaging solution, notification center and the long awaited over the air OS updates. With iOS 5 Apple also added their own reminders app, along with quick access to the camera from the lockscreen.

OS X 10.7 Lion was a major update, with over 250 new features to speak of. We saw such things as AirDrop, a proper full screen mode, Launchpad and Misson Control introduced, along with the brand new Mac App Store.

Then of course, came iCloud. Not just cloud storage as such, iCloud replaced MobileMe and was to become a way to push all your content to all your devices. Contacts, calendars, photos, apps, along with the facility to backup your device. All Apple customers would get a free iCloud account, and iTunes even got involved with iTunes in the cloud and iTunes Match.

So, that's 2011. As ever, share your own highlights with us in the comments below! Just one more day to go!