While e-mail is increasingly blurring the lines between Americans’ work and home lives, it has also led to more flexibility and most workers don’t believe it has added significantly to their overall workload, according to a recent study by the Pew Internet and American Life Project.

Fifty percent of employed e-mail users say they check their work-related e-mail on the weekends. Also, 22% said they check their work e-mail accounts “often” during weekend hours, compared with 16% who reported the same in 2002, according to the report dubbed Networked Workers by Mary Madden and Sydney Jones.

Also, 46% of employed e-mail users said they check email when they have to take a sick day and 34% said they will at least occasionally check their e-mail on vacation, according to the Pew Internet Project.

However, most employed e-mail users do not believe that using e-mail has increased the amount of time they spend working, according to the report.

Just 17% attribute some increase to e-mail, while 6% believe e-mail has cut the amount of time they spend working, the report said.

Also, not surprisingly, American workers aren’t using the Internet at work solely to do their jobs, the report said.

Shopping is the most popular non-job-related activity at work, with 22% of employed internet users reporting at least some at-work purchasing, the report said.

Other popular non-work, on-the-job Internet activities are watching videos and sending instant messages, with 12% of employed Americans saying they have engaged in those activities, according to the report.