Chelsea Clinton, 23, and Ian Klaus, 22, are back on, we hear. The former First Daughter was said to have wanted to cool things down with her Oxford University boyfriend. "She wanted some space," says a source. "But after a while, she realized how much he meant to her." The couple finished their final exams last week and have been celebrating ever since. We'll have to see whether Klaus, a Californian, follows her to New York, where she's due to take a $120,000-a-year consulting job at McKinsey & Co.