Alibali, I see no reason why the recipe couldn't be halved. But unless you're halving it because you don't have all the ingredients, why bother? It freezes well.

If you do halve the recipe, remember to cut the baking time a bit. Just keep checking it. It should still be jiggly in the middle -- it will firm up as it cools.

Aci, sorry but I didn't see your post. I've tried putting the springform pan right in the water, but the pan leaks a little and lets water in. I also tried wrapping the outside of the springform pan in foil, but that wasn't so great either. So, I end up doing what Samantha said to do -- put a separate dish of water either on the same rack or on the rack underneath.