Although my old phase detect DSLR had no trouble tracking kids-in-play at close range and with poor indoor light, my E-P3 is pretty bad.. very hard to actually achieve focus lock.. So I tried zone focussing.. I had the 14mm on, pointed it at a toy about 2.5 ft away and half clicked the shutter button, switched from S-AF to MF (I setup the record button as a short cut for this)... then clicked away making sure the kids were approx 2.5 ft away from the camera... considering I was shooting at f2.5 the whole time, I'd say that at web resolution, at least 90% were sharp enough... But the one thing that I realized was that waiting for focus lock meant I got a lot less photos which had better focus... but zone focussing meant I got a lot more pictures and didn't lose any moments, at the cost that some of the pictures weren't tack sharp... I think that's a reasonable tradeoff - I'd rather have a picture of a precious moment that may be slightly soft than lose the moment because the camera was confused.. What other techniques are useful for kids-in-play?