Walking Tall

So after reading this months people style watch, I came across the article about super high heels. It got me thinking how high is too high, and still considered wear-able? As much as I think these 5.5" heels look super hot, making legs look impossibly long, I honestly dont think I could do it. Maybe if I was going to a dinner only thing so walking was super minimal? But For now I think my limit will be 4". Soo what do you guys think, whats your limit?

Gwyneth Paltrow seems to like rocking the super highs. Pictures found from google and neimanmarcus, last two are both Louboutins.