Tasks are usually brief and may include communicating (via email, facebook, twitter, blogs), shopping, performing research, online banking, etc.
Jane: "I'm sorry, I can't. I have a bunch of internet errands I have to get done."
Ex 2: Jill: "Jack it's 8pm, you're still wearing your pajamas and you haven't left that computer! Have you been wasting all day surfing the web?!"
Jack: "Whoa, chill out, I've been busy. I paid the bills, emailed John and Jane about camping next weekend, booked us flights to visit your parents, posted some items to sell on craigslist, bought a groupon to your favorite restaurant, submitted my research paper, and I ordered you that necklace you were eyeing at the store for half-price off of amazon.com."
Jane: "Well, I cleaned the tub."