I just got a DS409+ from Synology. What a perfect little unit for a small business!
The upshot of this is that for about $1500 you can have a 6TB RAID-5 box which allows you to run a small local web site (and runs PHP, so you can install a blog or wiki), allows you to create a shared file system which can be controlled using group permissions (so common shared files can be shared in the office), and have plenty of space to use it as a Time Machine server. It also will run an e-mail server, and you can even set it up to use DDNS.
I definitely will be getting one of these if I ever open a development office, so we can share common development tools and have a way to back up the office.
Naturally, of course, I probably could have hand-built all of this for less in a cheap Linux box. But the beauty of this is that it’s a self-contained and quiet little box that’s relatively easy to set up. This little guy is going into the basement so I can back up my my laptop, desktop, and my wife’s desktop machines.