They freeze brilliantly in little freezer bags. Iv had breadcrumbs go mouldy when iv put them in a sealed box, but i think they weren't dryed out properly and thats why. Iv kept crumbs that iv dried out in the oven in a zippy freezer bag and they kept well until i used them up in about a month or somthing. So i think if you want to keep them unfrozen they have to be properly dry and not fresh crumbs, if in doubt just stick them in the freezer and they'll keep pretty much forever wither they are fresh or dry.
Tim Minchin - The Good Bookhttp://www.youtube.com/watch?v=kr1I3mBojc0
'If you just close your eyes and block your ears, to the acumulated knowlage of the last 2000 years,
then morally guess what your off the hook, and thank Christ you only have to read one book'