Those of you who know me probably know that I am obsessive and excessive over data backup. I have two separate external hard drives (so I can have a backup of a backup, as if one were not enough) where I keep an archive of all my files I’ve accumulated in this lifetime. Whenever I have a document that’s a work in progress, I obsessively email myself an updated copy at least every couple hours in case my computer crashes. Ok, so you get the point.
Now, instead of emailing working files to myself, I can simply use Dropbox. It’s a pretty new service, and I’ve just started using it, but I would definitely recommend it based on what I have seen so far.
Dropbox currently offers 2GB of free storage without advertisements per free account. That’s probably not enough for all your files, but it is definitely more than sufficient for working files that are not yet archived for the average individual. There are also a couple paid upgrade options, but I feel like 2GB is more than enough for my needs as long as I only store current files. Refer a friend and receive 250mb of extra storage per friend (If you do happen to sign up, then please use my link). They also feature a public folder option so that you can share files with your friends/family. This feature is also ideal for group projects with files that need to be accessed by more than one person.
You can access your storage account via browser or directly from your file explorer, available in Windows, Linux, and Mac, as long as you download their software. I definitely prefer the drag and drop file explorer, because it’s so well integrated that it feels like I’m copying to an internal drive!
Here are some screenshots (click pictures to enlarge):
I am running Ubuntu 9.04 Linux in this screenshot. You can see your folders and files almsot as if they were on your hard drive, but…if your hard drive crashes, the files will still be safe!

Wow, I have to admit that I’m a rare breed. I’m currently both a Linux and Windows 7 RC user. What’s up with that? Anyway, in Windows file explorer, you get roughly the same effect. Sorry, no Mac screenshot, but Mac users, I think you get the point. I’m not trying to be anti-Apple here, but I definitely can’t justify paying for most Apple products, so I’m sticking to Windows (when it’s free or included) and Linux.

If you prefer, or if you need to access your files on a computer without the software installed, then there is also a browser view option where you can upload/download files directly to on the dropbox website. Not as convenient or aesthetically pleasing as the drag and drop software, but it works.