Mamoworld, home of Mathias Möhl and friends, has published a new quick tip tutorial (embedded below), Modifying Keyframes with KeyTweak. Mathias says that KeyTweak is a must-have when working with hundreds of keyframes, like in his stabilize motion tutorial. The new version is easier to use -- you can push around keyframes in the work area just using the Arrow buttons.
Although the new version of KeyTweak was published last December, I didn't have a tutorial about its new features (the new "local mode"), hence almost nobody discovered its potential so far. While the old version of KeyTweak (consisting only of the "global mode" of the new KeytTweak) had a somewhat confusing workflow (you needed to duplicate a property, delete all keyframes in it that you want KeyTweak to take care of etc), the new local mode is much more intuitive.
With a set of arrow buttons you just move around all keyframes in the work area, and also fade in/out those changes if you like. The old "global mode" remains still useful for properties that are not 2D, like transparency (local mode works only with 2d properties and mask shapes).