I like to use a standing desk
Some famous people have been known to use standing desks. Benjamin Franklin, Thomas Jefferson, and Winston Churchill for examples. According to Wikipedia, standing desks were popular in the 1700s, so maybe it’s true about the Founding Fathers. I like to use a standing desk because it gives me a sense of urgency and momentum.
A box on your normal desk moves a laptop to a comfortable height for typing while standing, and it makes a reasonable kludge. There are other suggestions out there by some other bloggers.
If you move your chair out of your office, I suspect you will discover that random surfing-of-the-internet disappears from your life. It’s much less fun to seek idle entertainment while standing. If you are standing up and your writing or programming hits a lull, the immediate impulse is to go do something rather than alt-tab to a browser and see what has happened on Slashdot or Reddit.
Sitting a lot is definitely bad for you. Kick the chair habbit. There are studies that suggest sitting shortens your life. I think standing most of the day and using a stool for breaks seem to make my back feel better. Others agree.