The above statement is very true. Care packages really are made to be shared, unless you can sneak it back to your cabin without being seen. And if the said care package contains Malteasers - you will RUN WITH IT!
Never underestimate the wonder and importance of food (especially candy) from your home country when you are at camp. Trust me when I say, any mail is good mail but a care package is the greatest thing you will get in your day! Ask friends and family to send you things like Cherry Ripes, Mars Bars, Crunchies, Chupa Chups and Smith's Chips. Not only are you going to miss these things in the most serious fashion imaginable but they are great to share with your campers.
While the most popular food that Aussies bring over to the USA with them is Vegemite it is definitely not the most popular amongst the Americans. If you really want to win them over come loaded with a few packets of Tim Tams. At camp you will instantly be the most popular person if you have a few of these babies on hand. And don't forget to teach them how to suck hot chocolate through the Tim Tam - this makes for great competitions.
Other fun things to make and bake are pavlova, damper and lamingtons. All of the ingredients for these are pretty readily available in a local Wal Mart or supermarket and they are pretty easy to cook. They taste great and are a good insight into Australian cuisine.
Mail is a huge deal at camp. Every day your campers are going to ask you at least 100 times for their mail. And at about week three it can get a bit sad if you haven't gotten any mail at all. Encourage your family and friends to write to you; even if it is only a post card. It helps with homesickness and is a great fun way to stay in touch.
Most of your camps will stock stamps or you can buy some at the local post office. The average price of international postage is $1.05. You will find yourself writing more than you have ever written in your life. Remember that many camps have little to no internet access and the best way to stay in touch is good old fashioned snail mail.