I use UITable to layout a form like UI, so the row size can match the content size.
There's an issue for UILabel only rows, that I need some extra paddings. The workaround is that wrap the row with a dummy UISlicedSprite background object, which describes the row size. Then disable the UISlicedSprite component, so it's not get rendered. A bit complicated and if the UILabel size changed, I have to manually calculate UISlicedSprite size.
I wonder shall NGUI add a box concept like the one in HTML/CSS. So that each UI element have a padding concept and know it's actually size. Then UITable / UIAnchor can aware of that property.