I graduated from the English Department in 2004, but always had a passion for the internet. After dabbling in non-profit, government and branding work in DC, I switched coasts and settled in tech-friendly San Francisco in 2007. Since then I've worked for a variety of startups and web companies, including Scribd and Flickr, and now work as a freelance product designer with clients like Lift, Airtime, and bitly.
Basically everything. It's amazing that I get paid to do what I always did for fun in my spare time–move around pixels, design new ways of organizing data, and, well, create products. Web design is an interesting form of product design: the marketing and brand aspects are an intrinsic part of every decision as much as the interactions, unlike, say, a tire, which looks like a tire no matter how pretty the box is.
Medieval and Renaissance Lit. I knew it wasn't practical, but I also knew it'd be one of my last chances to study older literature.
I always felt very supported by the professors at Mason; it was a nice early lesson that people in positions of power (e.g., managers and bosses) generally are very reasonable, and want to help you.
My writing skills come in handy all the time. Web designers, particularly at small companies, are not only in charge of Information Architecture (a fancy way of saying we write the outline of the site) but also initial copyediting, and of course most of the vernacular on the site.
Writing research papers was also incredibly good practice for my job. Web designers observe (and observe and observe) and listen and extrapolate user goals from what users are saying. The two aren't often related. Critical faculties are key.