One place you often can not blog is both while in class and during your work time. Updating your blog during your work period and class can often result in some quite serious consqueunces, like being fired or smething as simple as getting yelled at by the professor.
How I Used to Blog at Class and Work
During class, I found that the best way to blog was opening up a text file and simply tping there. It makes it seem as if you are really typing notes, whereas you are really gettig your blog typed up. Sometimes I even mix in my blogging with my actual reports, so if anyon took quick glance at my work, it would seem ordinary.
The main point is to disguise your blogging to the point where it looks as if you are working hard.