Hurrah – here's a Hollywood hair trend we might all be able to pull off! First 'glunge' – that's glamour meets grunge – took over the fashion world and, judging by the A-listers out and about this week, now it looks like it's fast becoming the summer go-to beauty trend. Nicole Richie and Sienna were co-creators and since then we've seen Lauren Conrad, Cameron Diaz and Lily Cole all follow suit. The rules? Centre parting is a must, plus loose waves à la mermaid style and mid-length hair. We're predicting this will be the festival look of the summer with Sienna returning to her boho days we all loved so much. But seems it's good enough for the red carpet, too.