There are a lot of uses, even if you only have 1 computer, so please keep reading as this may interest you. If you've never heard of dropbox, you can find out more about it at the official site www.dropbox.com or click here to jump to their "tour" page that describes it or continue reading below about why I love it and it's potential uses.
Before I get into meat and potatoes of this, if you'd like to sign up for this, please consider using my referral link below. Not only will this help me but this will also benefit YOU. For every person who signs up through this referral link, I get 500mb of additional space and so do you. So using this link will give you 2.5GB of storage to start with instead of the normal 2GB :)
Referral Link: http://db.tt/fTnVFrRS
General background on what Dropbox is
The general gist of what dropbox is, is that it's probably the easiest way to store , sync, and, share files online (it's effectively cloud storage space). There’s no complicated interface to learn, it works seamlessly with your operating system and automatically makes sure your files are up-to-date. It's available for Windows, Mac, and Linux platforms and also some mobile phone platforms (iPhone and Android for instance). You can sign up for free and start with a 2GB account, which you can increase for free by getting referrals, taking part in annual events, completing some tasks etc... with an upper cap of 16GB (if it's a free account). You can also pay for a premium account and get 100GB, 200GB or 500GB accounts for a reasonable monthly fee.
When you install Dropbox, the software will create a specific dropbox directory on your computer and only files put into this directory are synced to the Dropbox cloud. Dropbox is perfectly secure but if you're a little paranoid (like me!) and you don't want sensitive data (for instance finance spreadsheets) uploaded to the cloud, it's simple: don't put those files in that directory and they won't get synced to the cloud :)
That's what it is, but what can you use it for?
-- The first one is pretty obvious. Backup storage! --
If your computer hard drive ever crashes or if you ever accidentally delete a file (and empty the bin on your computer), you can just log into your dropbox account and recover the file(s).
-- Synching files across multiple computers/devices --
This is another fairly obvious one as it's something dropbox advertises quite a lot. I you install dropbox on multiple computers (they can also be a mixture of platforms like Windows, Macs, Linus and phones!) and tell each one to use your account, it keeps all the files on each computer in sync with one another automatically. No more having to keep transferring files on USB from the desktop computer and then copying them to your laptop manually. So if you make a file on your desktop, update it and then go to your laptop, the laptop will have the updated one ready for you. And vice versa.
I have this on my iPhone and Android tablet too. Frequently myself and friends will show each other files we've been working on (videos, pictures, music etc...) through Dropbox on our phones, as we always have our phones on us and we don't have to even think about transferring files and keeping them up to date, Dropbox does that for us automatically.
-- Sharing files online --
You can use Dropbox to share files from your account for other people to access. Again, myself and friends use this to show what we've been working on and get some feedback. I also use a it a fair amount at work, when we have to send large files to clients. I believe there is a limit on how many times the file can be accessed a day, so I wouldn't use this to host CSS files or resources for your website, but as a general tool for sending or sharing files with specific people, it's great.
-- Versioning your files --
This is probably one of my favourite uses. When you modify a file in the Dropbox directory, it actually stores them as a new version rather than replacing it completely. So you can log into your account and see all previous versions and even download older versions of your files. There probably is a limit to how many versions it will retain before it starts overwriting the oldest, but I'm sure I've seen at least 30 older versions listed for project files before.
For instance, I frequently use this when I start a new project. I create a new sub directory under the Dropbox directory and will have my project files in there. Every time I modify one of these, it will sync and create a new version of the file. So if I'm creating a 3D model and changed something quite drastically from what it was 2 weeks ago, but wanted to see what the old version was like, I can download the older version of the file from 2 weeks ago. I can either choose to restore it so it overwrites the file I have in the Dropbox directory or save is somewhere else with a different filename so I have both versions. Pretty cool feature.
So there you have it
Dropbox is a great FREE tool. I'm sure there are lots of other uses out there but these are just a few I would like to highlight. You can also get a little creative with it and find other ways to use it.
For instance, I set this up with a few friends to keep a "Terraria" (http://www.terraria.org/) game world in sync with one another. Normally, one of you would have to act as the "host" of the game world and all the data is saved to their computer and only their computer. So if there was 3 or more people, the same person who is the host has to always be available if the others wanted to play that world. What I did was got them to all install dropbox, and then I created a new "shared" folder with them so that whatever we put in there, is synched to all our computers (even though we each had different dropbox accounts). I then got them each to run a few commands to create a symbolic link from this folder to their Terraria game folder and then we were all set up to go. Anyone one of us could act as the host and we would have the most up to date game world file available. So if one person couldn't come online or even if someone just wanted to play the world level on their own, there was no problem as the most up to date world data was always on all of our computers instead of just 1 persons.
Again, here's my referral link if you're thinking of signing up to Dropbox. It will give both YOU and me an extra 500mb of data for free!
Referral Link: http://db.tt/fTnVFrRS
Once my account hit's 16GB (which is the upper cap of free accounts), I'll remove the refferal link as it probably won't work anymore, but I'll leave this post up as I do truly believe Dropbox is a great tool for people to use.