From BlenderWiki
Mirror IPO Curve Points
This feature mirrors the selected keyframes in the active ipo curves over a user-nominated mirror-line. One time where this is handy is when creating ipos for driven shape keys, where you often have a left and right shape for something, where one of the curves is the opposite of the other. Rather than manually moving the keys or scaling them by a negative scale factor, you can now simply mirror those points.
Options are: - Mirror over current frame - Mirror over vertical axis (x = 0) - Mirror over horizontal axis (y = 0)
Functionality can be accessed from: - Hotkey ⇧ ShiftM in IPO editor - Submenu in header of IPO editor
Grab - Axis Locking
Transforms in the IPO editor lacked support for axis locking when performing transforms. This created confusion and annoyance due to lack of consistency between different parts of Blender.
It is now possible to only tranform selected keyframes/curves along a certain axis by pressing the key with that axis' name (i.e. X for only along x-axis, Y for only along y-axis).
Smooth Ipo Curves
This tool 'smoothes' the selected keyframes in the selected ipo-curves.
It takes the mean (average) value of the keyframes, and repositions each keyframe half-way between this average value and the keyframe's original value.
Hotkey for Smooth IPO is ⇧ ShiftO
