The SP-310 has a fairly conventional, conservative design (with a smidgeon of - dare I say it - Canon PowerShot about it). It's an all-plastic body, which keeps the weight (and presumably price) down, but feels very rugged and able to take the knocks compared to some of the shinier metal-skinned models on the market. It's also light (180g without batteries) and very compact compared to most budget models (the nearest direct competitor, the Canon A620 is a little bigger, and quite a lot heavier). There's a fair amount of external control gear, which makes manual shooting a lot less painful than with many models.
In your hand
The SP-310 feels remarkably good in the hand, the weight is very evenly distributed, so it's well-balanced, and - as long as you don't mind the warm feeling of an all-plastic body in the hand - it seems very well put together and certainly doesn't scream 'budget model!'. The handgrip is large enough to make the SP-310 feel very stable - this is one of the only cameras I've used in recent months that feels stable when held in one hand.
As is now increasingly common with Olympus compacts, the SP-310 ships with a non-rechargeable CR-V3 battery. The battery compartment also accepts two AA cells, and we'd advise picking up a couple of NiMH batteries and a charger if you intend to use the camera seriously. The battery compartment cover is a little tough to open, but it does have a locking switch, so you can't accidentally knock it open.
The xD-Picture card slot sits under a sturdy cover on the side of the grip. I'm not a huge fan of xD; it's slow (especially the new type-M cards) and much less commonly available than, say SD, but for the average user needing only one or two cards it's hardly likely to be a deal-breaker.
The SP-310 doesn't actually ship with a card, but there is around 25MB of internal memory (enough for 5 SHQ best quality shots).
Tucked away above the battery compartment are the SP-310's connections; a combined USB / AV port and the socket for the (optional) mains adapter.
The small flash has a range of around 3.8m (Wide) / 2.2m (Tele) - pretty standard for this class of camera. On the other hand it works well at close distances, throttling down perfectly down to about 10cm. Our only major complaint is the recycle time, which can become a bit of a drag when shooting socially - with red-eye reduction activated you're looking at about 7 seconds between shots.
The SP-310 sports a small 38-114mm equiv. 3x optical zoom lens that protrudes just over an inch from the body when powered up. At F2.8 - F4.9 it's on the slow side at the long end, which can be a problem when shooting in low light unless you're using flash.
The 2.5-inch TFT screen isn't up to the standard of, say, the Stylus range, being nowhere near as bright and only sporting 115,000 pixels. But it is very clear and suffers only the barest perceptible lag. The plexiglass cover helps protect the screen against damage, but does cause glare problems in bright light - something not helped by the slightly dim display. For a budget camera there's nothing to complain about, but there are certainly brighter screens out there.
An increasingly rare sight these days is an optical viewfinder - useful for shooting in very bright light or when battery life is getting low. It's small, has no diopter adjustment and it only shows about 80% of the scene... but it's bright and clear and is no worse than any other camera!
To the right of the viewfinder is the main on / off power switch.
The ubiquitous 4-way controller - located to the right of the LCD screen - is used to navigate menus.
On the top of the camera sits the large main mode dial. Here you can switch between the various recording and playback modes.
The shutter release sits in the middle of a circular zoom rocker switch on the top of the hand grip.
In addition to the flash, display and quick view buttons near the corner of the screen is a 'custom' button (marked AEL, for its default function) that you can assign to pretty much any shooting variable, including ISO or white balance.