Sweltering is the only word to describe this afternoon in Burbank, one of those sticky, no-breeze days that makes people hate the San Fernando Valley, but you wouldn't know it from looking at Rebecca Romijn, who is standing in the doorway of her trailer on the Warner Bros. lot with a big, broad smile. Hello, hello, nice to meet you, come on in, she says, learning way down to shake my hand. Romijn is nearly six feet tall, a lot of that legs, but now, perched at the top of several steps leading up to her aluminum-sided home away from home, she's about twice that.