I was actually going to ask what you thought was the best way to label plants? I plan on photographing them with their ID when they arrive. I want a way to keep track of them when they are all in the tank as well as out for watering. I'm sure with time I will learn what is what, but I don't wanna lose track of their ID's before reaching that point. haha...
If you are not too concerned with cosmetic appearances, you could physically attach an id tag to the plant or the plant's mount (tags can be as simple or sexy as you want to make them). Tags are used frequently for Tillandsia grown outdoors, and inside greenhouses. They are attached directly to the plant, mount, or growing trays, and most are nothing more than a small plastic tag marked with a sharpie.
Another option, if you don't want to see tags hanging everywhere, is to set up some type of file (computer, or even an 'ole' manual sheet of paper and pencil). It could be a picture file with id's, or just a list of the specie's names and a number (e.g., stricta #1, aeranthos#2). If you know where your plants are being placed or mounted, you could also make a crude drawing (of their placement) and place a number on the drawing so you know what is what, and where they are located.
If using mounts, I sometimes take a sharpie and mark a number on the mount (that only my eye sees) to keep things looking good. I'm sure there are other good ideas out there. Here's a picture of one type of mount that I use (with a small number on it) to help keep track.