Spending hours a day sitting on your butt is not a great way to remain healthy ormore importantlylook good naked. But immobility is usually necessary in order to be productive at work. Here are a few ideas to get around this conundrum:
Treadmill Desk: You'll need a cool boss and a fair chunk of change to buy or construct one, but people who use them insist that they are incredibly effective, and that they don't interfere with work at all.
Walk-and-Talk: If you need to meet with someone in your office, suggest taking a stroll around the office (or even outside) while you talk. It's got the benefit of being free, plus you'll both be free of distractions like email pings. But it's not so useful if you're going over a documentor if your colleague refuses to get out of his chair.