hmm, right above where your pic is, your filter assembly sits there, might check all that, the filter for tightness, the filter housing or whatever you want to call it.
and because its on your headers, assuming its on the top of them and dripped down, I would suggest looking at your valve cover seal.
since its all over everything im sure, I would clean it up with rags as best you can, fill the engine back up with oil, and start it. then go look at where its coming from. with the car sitting still to, the oil wont be blowing all over everything, should just drip down and you may be able to see exactly where its coming from.
best way to find a leak is to try to re-produce it while your staring at the problem area.