My technique journal's been fleshing itself out nicely lately. I use Freemind's mind-mapping software. I chose it because it gives you a flexible way of noting techniques...and, well, I like charts:) They help you see things. It's been especially helpful in finding holes or areas where I've been placing proportionately more attention...or not enough.
It's solved my biggest problem when it comes to journals. I have WAY too many and keeping topics organized can be a hassle. On top of that, I have the bad habit of grabbing the wrong one when I'm in a rush. Little notebooks all over the place. Movement exercises, Spanish, Cooking, Mandarin, Spiritual, BJJ technique, Chinese group...tiny books all over the place. Now, when I learn a new trick to countering defense to armbars from the mount, instead of trying to squeeze information into the margins of that first, tattered page that I created for armbars, I can just go and modify the note on the armbar node.