Blogging is neither site specific nor time specific.
If you (or your students) are in a situation where you are traveling (teaching abroad, extended field trip etc.) blogging can be a good way to track progress. It also works if students are involved in class related activities outside of school - such as internships or field trips. Because it is not time specific, both students and teachers can access the material at a time that is convenient to them. Over your 8am coffee, at 1:30 in the morning when you can't sleep. During boring presentations (if you have internet access)
Some examples:
I could go to the Sundance Film Festival and keep a blog of my day to day experiences for the Film Festival Management course to read and respond to.
I could take the Film Festival Management students to Sundance and they could keep a class blog of their experiences and share them with those back at school.
I could take some of the students (those who could get time off) to Sundance and the remaining students stay in Florida. The students at Sundance could post about their experiences while the students in Florida could do internet research on the festival and post their information. This could include questions from one group that the other could answer.
I could take a group of student to Europe in the summer. I could give them a list of activities they are to do before they leave. (Go to 2 museums, one cathedral, see a play, travel on a train to another city etc...) As they complete the various assignments at their own pace in their own order, they can post about it on their blogs (complete with photos) and I can comment (as can the other students)
I could give the students a list of museums they have to go to before the semester ends with a list of questions they have to answer. They can post their assignments as blog entries.