Eddie B talked about the 'leg resting technique' during time trials in his book--during a time trial, relax alternate legs every fourth rotation.

Another good distractor, is focusing on unclenching and making a conscious effort to breath in AND out deeply. That sounds pretty ridiculous, but we tend to clench up when putting on the hurt, which constricts our trunk and makes deep breathing difficult.
If you can focus on unclenching and breathing deeply instead of on how much your legs are burning, you might be very pleasantly surprised. Another little trick my power meter taught me.