Storing Grains

Since I primarily brew small batches, I was wondering how you all store your grain? It doesn't make sense to buy 1-2 gallons worth of grain everytime I brew, so how is the best way to store un-milled grain? I live in HI, so humidity and bugs are issues, but up until now I have been storing it is large glass mason jars to protect it. Any idea how long it will last like this?

Thanks

Do you have your own mill? Otherwise you're going to have to go to Homebrew in Paradise to mill your grain anyways, so no point in storing it. But if you buy in bulk and have a mill, many people store unmilled grain in food safe air tight containers, that are used to store things like dog food. Like this http://www.petsmart.com/product/index.jsp?productId=2811537
Or if I recall, Mike just keeps things like his specialty grains in buckets with lids, so some Homer buckets from home depot would do the trick as well.
That would keep the cockroaches, geckos, stray chickens, mongooses, and moisture out.

Since I mostly brew-in-a-bag, I just crush it up real good myself rolling pin style. With this method the crush isn't as crucial because there is nearly no way to get a stuck sparge and no need for a great grain bed. Just have to be sure that the grains are all crushed. Also, because I'm doing a kg or so at a time, it isn't a huge deal to crush it up, 5 mins or so... I feel like a real jerk going to see Mike every time and only buying 80 grams aromatic, 160 grams crystal 60, etc...

This is for larger amounts, but what I do is leave the grain in the bag it came in, put it inside another bag, then inside a plastic bin with a lid.