How to mirror a walk cycle? How can we mirror a walk cycle, to make the bones do the same transformations but flipped, and offset in time?

Say I have keyframed the bones on the left side, and they're labeled as such (bone_L for example), and now I want to make the right side of the armature step in that same way on its side, half-way through the walk cycle. What's the most efficient way to do this?

I've been copy/pasting location and rotation values from the left bones over to the right bones and typing a minus sign in front of the values that need it, but it's a tedious process and easy to make mistakes.

Thanks
You may use the Paste mirrored keyframes from buffer button.


In 3D View window select all bones with A (or select only the ones you want to mirror). Do the same in the Dope Sheet Editor. Press the Copy selected keyframes to the buffer button (or Ctrl+C, while being in the Dope Sheet Editor), go to the frame where your half-side animation ends and press the Paste mirrored keyframes from buffer (or Shift+Ctrl+V).