An easy, fairly effective method of preserving a mushroom's potency. Punk rocks
I always store my mushrooms in honey, whether they're fresh or dried. Dried I usually chop them up, then let them set for a month or two for the entheogenic goodies to disperse throughout the honey. At this point, with enough fungus in the mix, the stuff looks like food. (Yes, I know...). This means you can take it anywhere, especially paired with a likely-looking bagel. Fresh shroomies seem to go into a state of suspended animation when dunked in honey, though some of the sparkles still end up in the honey itself.
[Erowid Note: Storing fresh mushrooms in honey can lead to excess water in the honey, which can result in either rotting or fermenting. Caution should be excercised when ingesting fresh mushrooms stored in honey.]