Check out this cool VaVaVroom cap: 100% cotton chino twill military-style. Flock logo. Adjustable Velcro® closure. $24.99
Va Va Vroom makes a lot of cool motorcycle gear for women, and I think this is a great looking solution for "helmet hair" as well as an anytime-at-all fashion statement.
There's more on their site. VaVaVroom.com
By the way, Denise Maple, founder of Va Va Vroom, is also a co-host on SideStandUp motorcycle radio.