When former Intel engineer Nick Bhavsar’s fledgling Web company began selling vinyl laptop covers with the Texas Longhorns logo and orders skyrocketed, Bhavsar realized he’d tapped into the growing demand for personalized laptop designs that are quickly vaulting the notebook PC out of its Model-T era. Apple Computer, Sony, Acer, Alienware, Voodoo PC and others have introduced more stylish designs, but the standard products available from the largest Windows PC vendors tend to come in either black or gray. That philosophy is starting to change. A few computer companies and several accessory makers and custom specialists have figured out that, like ’70s-era custom vans and dot-com-era BMWs, custom-look laptops can be seen as potent style statements.