If seeing all those noncelebrities on E!--the personal stylists, the restaurateurs--makes you seethe with envy, calm down. Where there's a will, there's a way you, too, can work it Hollywood-style. All you have to do is carve yourself an entrepreneurial niche that makes you an "expert" in something not many are. But expect some hard work, pavement-pounding and door-knocking, because, face it, if you're not Jerry Seinfeld's ex, immediate start-up exposure might not happen. Here, see how four Tinseltown-inspired companies got their big breaks.