NOVELTY phone design is only fun inside the shop. Remember that when you head for your next upgrade, or you could end up with a Nokia Crystal Prism.

There's a little ritual we like to perform whenever we get a new phone, and it comes in four phases.

Phase One is to unwrap the shiny nugget, drool slightly like the nerds we are, then intensify our excitement to fever pitch by slavishly following the instruction booklet and giving it a full charge.

Phase Two, some hours later, sees us switch on the phone and tear into its sub menus like a hungry hyena at a fresh zebra corpse to find the ringtone menu. Then we listen to each tone in sequence, chuckling to ourselves and marvelling at their hideous cheesiness with a wide-eyed, pitying wonder, before picking the funniest one as our default ringtone.

Phase Three begins at the precise moment we receive the first call on our new handset - usually somewhere public like a bank queue - at which point "Jamaican Beach Party" makes the instantaneous switch from hilarious novelty jingle to soul crushing embarrassment. The next time we are alone we head back to the ringtone menu and select the one which sounds most like "ring ring."

Finally, Phase Four commences, in which we never open any menu in the phone ever again, using the device solely for voice chat, text messaging and the clock. This lasts until the handset expires.

It's clear how the process happens. The sheer joy of playing with a new gadget has a profoundly muddying effect on the decision-making circuitry of the owner's brain, endowing objects, situations and sounds which would normally be avoided at all costs with a rosy aura of optimism and fun. Most worryingly, the phenomenon can actually be triggered before a gadget has been purchased. The result: instead of an easily rectifiable ringtone misjudgement, the sufferer is fooled into buying a phone which is itself inherently stupid. Cue embarrassment not just once in the bank, but for every single second of the rest of their life. Well, until they buy a new phone.

All of which brings us to the Nokia 7900 Crystal Prism. The Finnish telephonic ultra giant has always been at the forefront of experimental handsets and its latest effort continues that trend with a design which appears to have been dreamed up by a team of hallucinating pigs. Stats-wise, it boasts... well, we won't bother because if you're contemplating buying one you probably can't read. Suffice it to say that it looks like a three dimensional version of the image on this page, and comes with voice chat, text messaging and a clock. We can but imagine the ringtones.