I just left Incheon airport (Seoul). Amongst the various items that you would expect to be banned, like propane tanks, razor blades, and knives, there is a prohibition on taking batteries in your carry-on baggage.
I don't know if it is only Alkaline batteries -- my bags were searched, but they did not pull (or find) my NiMH batteries. The humorous thing is while my stuff was being searched, the person behind me put his batteries and butane lighter in a tray to go through X-Ray. Of course, the "dangerous" batteries were confiscated, but he got to take the lighter. True to the open source movement, they also had a detailed description of how to build a shoe bomb. I'm actually not being facetious here -- it actually explains what they are looking for.
