Well, the best way I have found to track down an oil leak on any engine would be to clean the area, and keep a close eye on it. Oil typically flows down (due to gravity) and back (due to car traveling forward/airflow traveling rearward), so if you can find the uppermost & furthest forward point that has oil, then you are probably pretty close.
I had an oil leak on my 2.3 that left the entire passenger side of the motor covered in grime. I followed it up from the pan, up the side of the block and head, and found that it appeared to be oil spilled on the valve cover causing it. I cleaned off the grime and dirt with some simple green and water, kept checking it each day for about a week (it's a daily driver) and found it was leaking under the valve cover gasket and up through the bolt holes, then down the side of the head, etc. I bought a new gasket, and replaced it the same weekend I did my timing belt.
Good luck!
--Doug