URL(s) to keyboard layout image(s):
http://mkweb.bcgsc.ca/carpalx/images/optimized-step_01.png

Single sentence description:
The QWKRFJ layout differs from QWERTY by 5 key pair swaps [E/K, T/F, N/J, O/L, Y/J] but is nearly as efficient as the Dvorak layout.

Full description:
This layout is generated using carpalx and in the same manner as the X-Fu layout. Instead of allowing all keys to be remapped - and potentially sending the candidate typist to the stone age of speed - this layout adopts only the 5 most effort-reducing key swaps. QWERTY is widely acknowledged as being inefficient for English text (and it has been created precisely with this fact in mind). Its drawbacks can be largely mitigated by performing a limited number of key remaps.

By swapping E/K, T/F, N/J, O/L and Y/J (in that order) the QWKRFJ layout results. Each of the swaps reduce effort by 16%, 14%, 8%, 6% and 4%, respectively, over the previous iteration. The final QWKRFJ layout improves on QWERTY by 41% (according to my typing effort model). This is a meaningful reduction given that only 5 key swaps were performed and the fact that the maximum reduction, offered by X-Fu is 54%.