Slouchy Copy Cat Hat by Terra Jamieson. The pattern is very well written and the hat was knit up in no time. I used just a little less than one full skein of Malabrigo Merino Worsted. Knit on 4.5mm (US 7) circulars.
I think the eyelet mock ribbing is really suitable for a spring/ summer version of the hat and I might knit one in cotton/ linen mix. Have you seen Starr or Cheer from the new Kim Hargreave's book? I've never knit a hat for summer, but now I suddenly need one.
P.S. Sese, matai, kokios kasos? ;-)