We use Dropbox at work and I also use Dropbox personally. Prior to just recently, to use both of my Dropbox accounts, I had to use DropboxPortableAHK alongside the standard Dropbox client (for Windows). It worked about 99.8% as well as I wanted it to. Every now and again, the portable version would get stuck updating itself. I'd have to kill the process and relaunch it.
Now, Dropbox lets business users link their personal account... this makes things much easier. I always like to use the official software with the various services I use in my internet/cloud living.
So if you've been wondering about how to use both business and personal accounts, your answer is now officially supported by Dropbox.