Personal journal software is the preference of many people including myself, at least for general everyday journaling.
Some good reasons for journaling online are:
Privacy (password protected)
Can't misplace it like a physical journal
Cross reference for an organized record keeping system
My own recommendation for journal software is LifeJournal. I've been using it for years and refer to it all the time for one reason or another.
For instance, I have a mentally disabled child and this journal has been a godsend in recording her behaviors for a doctors review. Or, if I want to find out when I attended a particular event...I just quickly look it up. It's extremely handy!
LifeJournal also has a section on Dream Recording :-) Even though I write my dreams down manually and don't use this feature, this could be a great tool to watch your dreams as they coincide with your daily life.
Here's the link to LifeJournal where you can download a free trial version and try it out. Also, be sure to check out their resources page for some good reads on journaling!