Dropbox is an online file service which gives you 2GB free online storage to store, sync and share any type of file, across many different PC's. You can also decide to share files or folders with other Teachers, for example reports for each pupil that have to be filled out by more than one class Teacher.
All you do is install Dropbox on each PC you use, for example your home PC and your Classroom Laptop, Syncing happens in the background over the internet, and basically anything you put in your Dropbox folder on each PC will appear on all your other PC's automatically.
You can also share whole folders or individual files with other users of Dropbox, meaning any files you place in those folders instantly transfers to those user' folders on all their PC's. any edits they make are reflected on your PC's too.
Dropbox's no nonsence approach means you get a very clean and usable interface both with their desktop application and via the website. You will never need your USB Pen Drive again. You get 2GB free, but if this is not enough, you can upgrade to 50GB for $99 a year, the software works with Windwos, Mac and Linux.
To get a 2.25GB Dropbox (thats an extra 0.25GB) visit this link
https://www.dropbox.com and download it to get started.