Sexy librarian chick and/or hot "study buddy" classmate. With neon orange panties.
UPDATE: 6/10/09 Refined the lines and details a bit.
UPDATE: 7/21/09 There was actually an error in the shading of her hair and neck. In the previous version, there was no shading behind the hair hanging over her right shoulder. To remedy this, I flattened the appearance of the hair but shaded the neck covered by the strand of hair hanging loose. Realized this while chatting with =violentsamurai