Sure, jim. And thanks.
Last week, the battery drained overnight on my '95 Civic 1.6L. I took the battery to be recharged at a shop, and we found that the water level was low. But I suspected a "ground" somewhere, because I had just sprayed the engine with a degreaser and rinsed it (low pressure garden hose).
Since my ammeter only goes up to 0.25A (250 mA), and I read on some posts that the current could go over 1A, I tried the bulb trick first. I don't know the exact rating of the bulb (aftermarket dome/trunk light), but it glowed brightly. (All doors/trunk was closed, key off)
I tried pulling underhood fuses and even disconnecting the alternator, with no result. Then I tried pulling the cabin fuses, and I found that it was the Pioneer head unit that was pulling most of the power (for the preset memory, I guess).
When I disconnected the radio, the bulb was finally very dim. I tried the ammeter and expected less than 80 mA (from the battery FAQ link, thanks to TeGGer). But I still got 170 mA or so. I've checked all the possible bulbs, and I think a bulb would pull more than that.
I finally concluded that there was no parasitic drain at all, but I'm puzzled as to what could be making that extra load.