Diploma frame from the graduate's school. Whether your graduate is going to run her own company or have a small office in a mega-company somewhere, they'll most likely want to display their diploma proudly for all to see -- and for years to come. Many campus bookstores offer diploma frames with college or university logos that will add that extra "pop" to your graduate's official degree.
Shadow box. Many craft and frame stores offer "shadow boxes": a box that has one side made of glass (made to look like a frame) that you can hang on a wall. Create a special one tailored just for your graduate -- with mementos, college insignia, and even sports paraphernalia, if appropriate. As an added bonus, shadow boxes work well in an office or in your graduate's new apartment.
College memorabilia. This can include anything that best fits your graduate's personality and interests: a sweatshirt, a workout outfit, a duffel/travel bag, an alumni bumper sticker, a portfolio, or even a clock. Many campus bookstores stock up on these kinds of items around graduation day, so there should be plenty to choose from.
Business card holder. Your graduate might be working for a non-profit or for corporate America. Either way, they'll probably have business cards they'll want to hand out at conferences, meetings, and other business events. Consider buying a small, nice, classic business card holder -- some can even be personalized -- as an inexpensive but highly useful graduation present.
Engraved pen. This is one gift that never goes out of fashion. Many companies offer very nice, classic-looking pens that can also be engraved. (Some college bookstores, too, offer similar pens with tiny college logos somewhere on them.) These pens work well for business interviews -- and, of course, your graduate's first day of work.