TO get waves in her naturally straight hair, Kristi Koren, 36, used to dampen it, twist it in dozens of curlicues and then sleep on it. But after seeing Anne Hathaway’s effortlessly voluptuous locks in “Love and Other Drugs,” Ms. Koren, a mother of one 13-month-old and an entrepreneur in Raleigh, N.C., began wondering if there were a less time-consuming and a less uncomfortable way of creating long, flowing curls. As a child of the 1980s, it didn’t take her long to come up with the obvious (and yet terrifying) answer: a perm.