Starting today you can upload videos from your phone’s media library and share those moments to Instagram regardless of when they were captured. Once you select the video clip you’d like to import, you can trim it down to the exact part you like best. We’ve also made it so that you can choose how you square-crop your clip so you can keep the action front and center.Instagram's 4.1 update also includes a new automatic straightening tool, which uses an algorithm to automatically straighten photos taken within the app when the Straighten icon is tapped. The tool also includes a slider that allows users to rotate and adjust all photos, including those imported from the photo library.
Instagram for the iPhone is a free app that can be downloaded from the App Store. [Direct Link]
Update: Instagram version 4.1 is now available for download.