Why, of course we can, Daniel! That's why we're here.Can you god blessed brains explain in some easy-to-understand way what are the possibilities for a Mac mini server for us non-tech brained mortals?
I have personally used Mac minis as servers since shortly after the first G4 models came out on the market. In fact, at one point I personally had two of them at Macminicolo.net, a wonderful little company that was founded on the belief that Mac minis were great servers. I've installed at least a dozen for clients, and they are excellent for small businesses for the following reasons:
They're inexpensive. When you start looking at an Xserve, you want to start looking at mass storage and tape libraries as well. Pretty soon, the cost of a fully-loaded Xserve starts looking astronomical to a small business. That's not to say that Xserves don't have their place -- in fact, I have had two of my clients start with Mac minis and then move to Xserves when they found that they were outgrowing the mini servers. With the new $999 price point for a mini with an unlimited Mac OS X Server 10.6 license, two built-in 500 GB drives, and 4 GB of RAM, almost anybody can afford to own a server that provides email, instant messaging, calendaring, a wiki, podcast production, and more to a small workgroup.
They make it simple. The advantage of Mac OS X Server's software suite is power with a pretty face; it exposes the UNIX power of Mac OS X (including the industry-standard Apache, PHP, Samba and Jabber/XMPP stacks) with the relative ease of the Mac. While you can certainly roll your own server setup using conventional Mac OS X (either using Apple's shipped versions of Apache & PHP, or bumping them up), having the server administration tools makes everything a lot nicer. What's more, the standalone unlimited-license version of Server is a full $499, making this a straightforward bargain.
They're small. An Xserve requires a rack mount, or at least a small rolling rack. With a Mac mini server, I can just set up the box and literally hide it in a closet somewhere. It doesn't need a monitor except in emergency situations, and most of the time screen sharing works well to administer the mini servers.
They're real servers. A Mac mini server is not a huge server, but then not every business or individual needs a fully loaded Xserve. These are great for "power" home users as well, as you can use them as a backup server for every Mac on the premises using Time Machine, set up a recipe wiki and family calendars, even an email server for a family domain. Hook one of these up to a RAID storage device or two, and you have tons of redundant storage (although not offsite).
They're expandable. The number of ports on a Mac mini server is staggering; 5 USB 2.0 ports, 1 FireWire 800 port, and a gigabit Ethernet port that would work just great with iSCSI on a DroboPro.
They're energy efficient. Most servers sound like a jet taking off when you turn 'em on. The mini makes very little noise, and uses about 14 watts of energy when it's in an idle mode. Rather than heating your building with a traditional server, you can have a Mac mini server and see almost no impact on your electric bill.
A Mac mini server has a lot of possibilities, and I foresee a lot more small companies choosing Mac OS X Server as their server OS of choice now that this "server in a box" is available. A lot of ACNs had been setting up Mac minis as servers for a while, and now the concept has the official blessing of Apple.
I don't know if this truly answers Daniel's question, but it should serve to hopefully remove any doubt that a Mac mini isn't a powerful and useful server for small business.