I was getting annoyed with losing gels for my flash and juggling camera bags to find them so I looked for a holder that might store gels. I did find a very nice one like what I envisioned from Lumiquest but since my need was immediate I tried coming up with something simple and quick to make. The total build time was about 5 minutes.
This is made from a sheet of a storage page for negatives that goes into a three ring binder. If you have been shooting for a while (i.e. film) you may have sheets of these lying around. I just cut one to size with three storage slots available. One covers the flash head and the other two can be used for storage. I can get about four gels into the storage slots without difficulty allowing me to store a total of eight gels. The gels are just cut from sheet gel material, in this case from Rosco.
I have no idea if this will fit other flashes. The flash that I made it for is a Nikon SB-600 and it also works on my Sunpak 383 flashes. Also not that the sample pack filters from Rosco and probably Lee also are a little too wide and would need to be trimmed slightly.