Yes, as weird as it sounds, we've been doing some journal writing in math class. This may seem strange, but.... Why do teachers in other disciplines journal? For reflective thinking! Should we reflectively think in math class? I think so. Students need time to process the content we're covering, a place to ask questions that they may not be willing to ask in a group setting.
My brother-in-law Russ Goerend has a great post about a standards based journaling approach. (Good journaling article, and a plug for family!) Now, I've chosen to not grade the journals. I've written before about my grading practices here. I started with paper journals. Students many times forgot to bring theirs or such, so it was a paper mess for me to follow up with them etc.
But...., I made a transition. I created an edmodo group for my students. This has allowed me to give the students a reflective question and they can answer. What I like about it is the ability of other students to respond as well. This does take some of the protectiveness out of the conversation, but they can also just send me a direct message and it's not viewable within the whole group.
I also really like it for the ease of feedback, I can just click reply and send the student some feedback on their writing. This has allowed us to reduce the paper usage in our classroom as well as stimulate collaboration 24-7 .
I know there are other sites like edmodo, please share them so I can compile a list to share!