Elasty is described as 'Movie Toolbox for customizing movies on Mac OS X with many advanced features often found only in much more expensive video editing suites'. There are three alternatives to Elasty for Windows, Linux and Mac. The best alternative is Video Rotate. Other great apps like Elasty are FURNACE (Paid) and Video Rotator and Flipper (Paid).
Video Rotate allows you to turn videos! Do you sometimes use your photo camera or your iPhone to take videos? Did you ever take a video verticaly by mistake? Video Rotate allows you to turn it back in the correct direction, for easier viewing and editing.