In terms of connectivity, the front is well stocked and the usual USB, 4-pin Firewire, and audio ports are all present. However, being a bare bones system, there is no memory card reader so you'll have to buy a separate one to pop in the external 3.5in drive bay. Likewise, you'll have to source your own CD/DVD/HD DVD/Blu-ray drive to fit the spare 5.25in as well.
Round the back things are a bit more complete, with no extra expansion cards being required to get your system up and running. That said, only D-Sub output is provided by the onboard graphics so if you have an LCD display with a DVI input or want to connect up an HDTV, you'll need to invest in a basic discrete graphics card at the very least. The rest, though, is well catered for with four USB ports, two eSATA sockets, an 8-pin Firewire port, Gigabit Ethernet network connectivity, and five 3.5mm jack sockets, for 7.1-channel audio, all present.
Removing the lid, the insides of the case are shown in all their compact and beautifully manufactured glory. All the edges are either rounded or polished so there's no risk of cutting yourself when working in the cramped interior and, because the entire case is made of aluminium, it is both lightweight and strong.
Due to its cramped interior, the SN68SG2 uses its own custom motherboard, which we found to be very well laid out with everything just where you'd expect. Likewise it has a custom power supply that is rated to 250W, which will be enough to power anything and everything that you could possibly fit inside this small chassis. Also, given the lack of space, there isn't room for a conventional CPU cooler so Shuttle uses its own ICE2 cooler. It uses three heatpipes to draw energy from the CPU at the centre of the case to the radiator and fan at the back. As you'll see in our testing the effectiveness of the ICE is certainly up to debate, though.
Accessing the interior is a two stage process and adding components requires a bit of forethought, but is ultimately quite simple. First, the drive caddy must be removed, then the ICE heatpipe cooling system can be removed allowing you to add in your CPU, RAM, and graphics card. You then work backwards adding in the cooling mechanism, and the drive caddy until, hopefully, all your components are hooked up and ready to go.
In terms of graphics cards, as mentioned earlier, the SN68SG2 cannot take dual-slot cards (i.e. ones with big coolers) so any variant of nVidia GeForce 8800 or ATI Radeon HD 2900 is out of the question. However, anything below these should be fine so long as it doesn't require extra power from a dedicated six-pin power connector. For our testing we used a reference design Radeon HD 2600 XT and it fits perfectly. In fact, the holes along the side of the case align exactly with the intake for the cooler so it's kept well supplied with cool air too.