What's an Apple Tablet? I'll give you a clue: it's not the sort of vitamin infusion old men take to kickstart their doddering mojos. No, MacBook manufacturer Asustek has told the world that Apple is about to build a Tablet PC.

Using the CoverFlow touchscreen interface which has proved so popular on Apple's sainted iPhone, the Apple Tablet will be based on a patent Apple filed in May 2005. It will have Intel Core architecture and run Mac OS X 10.5, aka Leopard, aka the one with all the bugs.

So that's the technical stuff sorted (sort of), but one major question remains. Why? Having cornered the market in digital-audio players and user-friendly game-free PCs, Apple has already exposed itself to the white-hot heat of the mobile phone business. And Gawd bless her, the fruity one remains upright.

But why any successful company would wish to get embroiled in the car crash that is the mass-market Tablet PC defeats me. Perhaps it is Apple's way of flaunting its apparently bullet-proof success. After all, Microsoft's Tablet adventures have been conspicuous by their lack of success.