Right, back to puzzles because I have nothing substantial to say. Circumstantial evidence suggests I created this one in June.
This is one of a bunch of MellowMelon’s Double Backs. Draw a closed loop through all square centers visiting each bold-outlined area twice.
EDIT 2012/10/12 UTC+8 7:30 PM: Fixed (or should I say rewrote) the top right quadrant and bottom middle. I hope.