Part 2: What are the cool things you can do with it?
Sync to other computers
You can set up Dropbox to sync your files not just to the cloud but across multiple computers. Anything that is in your Dropbox account on one computer will be automatically synced to all of your computers.
Start writing up an assignment on your work laptop. Save the file in your Dropbox folder. Leave the laptop at work. Go home. Guess what's waiting for you on your home computer? That's right, the file that you created at work. Keep refining the assignment at home. Go to work. There it is. Mind-blowing.
Access from anywhere on the Web
You're meeting with a colleague and you need to bring up an assignment but you don't have your laptop with you? No problem. Open a Web browser and login to your account on dropbox.com. You'll see the exact same directory structure that is on your laptop. Click on the file you want to download and view it. Done.
And you can upload any file you want to your Dropbox account through a Web browser. And once it's uploaded it will instantly sync with your other computers. Upload via Web and it'll be synced to your school laptop the next time you open the lid.
Access from Web-enabled mobile devices
Out at the club and want to impress the ladies with your amazing Shakespeare PowerPoint presentation (hey, it could happen right?)? Take out your iPhone/Android/whatever and fire up the free Dropbox mobile app. Navigate to your Dropbox directory and download the file to your phone.
Or, more likely, you see a sweet grammar error on a huge outdoor billboard. Snap a picture of it with your camera phone and then "share" it to Dropbox (that option automatically appears once you install the Dropbox app on Android). It will deposit your image in your Dropbox account and you can pull it up at school the next day to show to your kids.
Share files without actually emailing the files
This one really blew my mind. Dropbox automatically creates a "Public" folder. Anything you put in there can be shared with anyone on the Web (don't worry, by default no one can see anything in there). You just ask Dropbox to generate a public link to that file. Anyone with that link will then be able to download the file.
Here's the mindblowing part: The recipient will download only the latest version of your file.
I sometimes find it necessary to tweak assignments. Usually it's to clarify an instruction. But once the kids have the assignment, it's usually too late to change things. But now I can post the public link to the assignment instructions (I have a class moodle site) and I can make changes when necessary. When a student clicks on the assignment link, she will see the most up-to-date version.
Consider another file that often changes: my gymnastics team roster. As the season goes on, kids inevitably quit or sometimes we actually gain a few kids. The activities office needs updated rosters at various points in the season. Instead of emailing them multiple versions of an Excel spreadsheet, I can just send them that one public link to my roster file. I update it on my school laptop. Dropbox syncs the new version to the cloud. The activities office can click on that same link week after week and will get the most up-to-date version of the file each time!
This totally avoids the confusion of, "Wait, you sent me three versions... which one should I look at?"
Amazing. There's no reason to ever email a file as an attachment again. And, as an added bonus, you don't clog up people's Inboxes with large attachments.
Next: Part 3: How I set it up