I noticed on a couple other forums as well as this one there had been questions asked about home made tank dividers, and we used to make these all the time in my Marine Science class to help separate out some of our more aggressive fish we didn't have tanks for, and to adjust new additions to tanks to familiarize them with the other tank occupants before releasing them all together. So here's a simple step by step guide with pictures of how we would make our tank dividers.
If you would like to repost this guide on another site you are welcome to do so. Please just credit me (Nataku) with it's creation, and link back to
DIY Aquarium Tank Dividers by ~nataku on deviantART
so that anyone else can also find this tutorial for future reference.