I have disregarded this app several times before as I do not see any reason back then as to what I'd do with it or as to what it can do for me. But the moment I tried it out, I have regularly used it since then. It's amazing how you are able to access your files anytime and anywhere as long as you are connected to the Internet. Your files are secured and encrypted over the cloud and if you have the Dropbox setup in your PCs, your files are automatically downloaded and updated.
If you wish to password protect your Dropbox folder in Windows, you will need to download TrueCrypt.