One of my major research interests is in how people of all ages, especially older adults (those over age 65) use the Internet (shameless plug for our new book on Designing Displays for Older Adults). The Pew Internet & American Life Project recent came out with a new survey of Internet usage across the age groups.
A counter-intuitive finding is that while those age 18-33 are more likely to access the Internet non-conventionally, it is a slightly older age group (34-45; my age group) that are more likely to engage in a wider variety of online activities.
The table below shows usage patterns by age group. Here is the full report.