I finally got around to finishing my cryptex the other day, and snapped a couple photos of it earlier using my phone (hence the lackluster quality of the pictures).
The cryptex itself isn't the most amazing looking thing, especially when compared to others in this thread, but overall I'm happy with how it came out, and will probably make another sometime in the near future (though possibly on a larger scale).
Some random notes:
-I bought a package of letter stickers at AC Moore, for 89 cents, and threw those on after painting everything. I liked that they were cut to the shape of each letter, not just squares/rectangles with letters printed in them. They're certainly not as durable as vinyl stickers, but...
-I bought a can of Valspar clear enamel spray, with the flat finish, and sprayed that on after putting the lettering on. I'm not sure if the gloss would've been any better, but instead of really adding a layer of protection to the cryptex, it seemed to cover it in a dusty/gritty substance. Not sure I'd recommend it.
-Unsatisfied with the Valspar spray, I gave all the outer/exposed areas of the cryptex a nice coating of clear nail polish (which is why it looks shiny again the pictures). I didn't bother coating the innermost tube, because I figured with it constantly sliding in and out, it was going to gradually wear down and scratch the paint away, no matter what I do to protect it. So that part will eventually turn white again in some spots (and, as seen in the picture, already has), but I'm fine with that.
As a container, for the time being, I cemented together these two Ziploc containers, with holes cut into the lids, and it ended up being a perfect length for the cryptex (when placed inside, it has no wiggle zoom, lengthwise). I may end up making a container out of PVC instead, but am concerned about how that might look/what it might be mistaken for.