This set of posts comes from Pastor Mark Driscoll and his wife Grace. The sermon series The Peasant Princess brought up dozens of questions that they felt they should respond to. The result is this blog series: Christian Sex: Frank Answers to Honest Questions.
Answer: Yes. The combination may physically heighten the degree of pleasure. For example, many wives cannot climax from normal intercourse but can climax from stimulation of their clitoris, which is not a point of contact during normal sexual intercourse. This can be pleasurable for both spouses, considering that most men are visual and this could be a display of visual generosity for him.