P.M.
Lots of empathy has worked well for littles I've interacted with. The Happiest Toddler on the Block, by Dr. Harvey Karp, talks about this approach. You can also watch a few quick videos showing how he does it: http://www.youtube.com/watch?v=fJ1428uYs2g&NR=1&a.... .
He demonstrates exactly how he "speaks" the toddler's language so they know he's heard the need they are expressing. This calms them and makes it easier for them to cooperate.