Luke Wroblewski posted about Developing the Invisible, an interesting article where he explain the importance of alignment and whitespace in the user interfaces design, the invisible part in the design.
Padding, or whitespace, often fares worse. In some places, padding is gone; in others, there is too much. Padding is set to different values, leading to columns and rows of varying widths. Changes in padding and alignment can negatively impact readability and obscure visual relationships that clarify how to use an interface.
Figure 1
