I don't think that there is a journaling class out there so it isn't like we're taught to journal in some conventional way.
Do you just write lines upon line, paragraph upon paragraph of what happened to you?
Do you write about ideas that you could attempt in the near future?
Do you draw or sketch?
Blogging has sort of replaced journaling. The problem with blogging is that sketching isn't as easy as just typing your thoughts. So we replace sketching with just finding and inserting some open-source or free image somewhere that approximates what we're trying to illustrate. Sometimes we're lucky and find a perfect picture. Most times, we're settling for a real stretch of the imagination.
Blogging platforms should take the iPad and other touch tablet devices as an opportunity to usher in a new era of blogging. Make it easy for us to sketch our ideas. No attaching images. No linking of image URLs. Just sketch it and forget it.