Dropbox is one of out favourite ways to backup and store files, but unfortunately it doesn't allow you to sign into multiple accounts at once. To solve this, blogger Daniel Mann figured out a way to run two different instances of Dropbox on a Mac using an automator script.
The process is pretty simple, and only requires you to cut and paste a single line into an Automator workflow. The end result is two (or more) separate Dropbox apps running and syncing your files, which is great if you have a business and a personal Dropbox account. To start, create a folder on your hard drive labelled "Dropbox-personal" in your home folder. Next, run Automator, select the "Workflow" option, and drag the "Run Shell Script" action into the main window. Then, paste this code in the shell:
HOME=$HOME/Dropbox-personal /Applications/Dropbox.app/Contents/MacOS/Dropbox &
Click "Run" to test the workflow and it should launch another instance of Dropbox. If it's working, save the file, and you're done. Whenever you click on that workflow you open up another instance of Dropbox with a new account linked to it.
Windows users can try the Dropboxen method to get the same results. Head over to Mann's blog to see how you can run the application at login, and check a few more tips on differentiating between the two icons.