Key Symmetrized Bone For Pose

If you have the x-axis mirroring on for pose mode and pose a bone, this moves the corresponding L_, R_ pair bone. However if you want to key that bone, it doesn't also key the other bone at the same time. I would like to be able to have an option to key both when I key once. I'm aware you could select all bones and insert a key to do it faster. However, I do not want all the other bones having added key frames.