I was recently asked to be a volunteer for a position which required me to carry a ton of keys. I needed something that would make order out of the crazy chaos. I ended up buying this key organizer: http://amzn.to/2Fh69lI
Here's how it came together:
Yes it handles odd numbers great. They have little washer like spacers that you can use to even out the two sides. Lets you use different thickness of keys with those spacers as well. They also sell extension bars if you have a ton of keys.
I saw that one, does it do ok if you have an odd number of keys?
Jared, I had a similar problem and went with Keysmart. Similar concept but made from aluminum. Http://www.getkeysmart.com It completely changed how I use keys. Especially those large number of volunteer keys.