Being a teacher often means that you do a lot of work from home to prepare for class. I finish up class presentations, write report cards and prepare lessons as often from my home computer as I do my school computer. Dropbox has helped me tremendously by allowing me to share folders between these two computers. Dropbox is a free folder that you install on your computer and that will allow you to share across computers. All you have to do is install it on whatever other computers (or smart phone or tablet) you use and all those files and folders you store in the dropbox are always available. Another great feature of dropbox is that you can share a folder with other people. I share folders with colleagues so that we can both have access to lessons we are collaborating on. It's also an easy way to share documents without the need of a memory stick. The free account gives you 2GB of storage but you can earn more space by completing simple getting started tasks or by referring your friends. If you use my referral link you will also be granted an extra 500mb of space. You can also subscribe to get even more space but I find that for my purposes the free account is plenty.