You could also spend the time googling tutorial or forum sites for the technology of your choice, either to get insight into "best practices" or to learn something new.
Another alternative is to actually avoid web-surfing and build some mini-projects of your own that might help you hone your own coding technique (assuming you're a programmer). Re-creating some program is a good way of exercising your understanding of the nuances of your language of choice. And you might build something useful.
Another possibility is to go to some site like gutenberg.org and read some classics. It isn't exactly work-related but there are scads of fine stories, biographies, histories, historical documents and other fun stuff.
And of course, you could also read and post on Daniweb, as @AncientDragon has suggested.