Last night's InStyle Summer Soiree was a hot L.A. ticket: "Such a stylish party!" tweeted Kim Kardashian, who looked amazing in a curve-hugging Victoria Beckham dress (left). Cat Deeley (right) arrived at the bash (after having just wrapped up the live finale of So You Think You Can Dance!) in a gorgeous J. Mendel dress and headed straight for our photo booth to mug for the camera. As guests like Michelle Trachtenberg, Amber Heard and Shenae Grimes soaked up the outdoor vibe, we asked them to tell us what they did on their summer vacations. Click through the gallery to find out!