At a hefty pricetag, the Prius conversion is now being offered in the UK, as well. I think I'd rather have the one they're converting at the Make Faire. But at 130 mpg and a 30 mile range on electric only, the plug-in may be just what London commuters are looking for, especially if they get the congestion charge exemption.
Plug-in Prius now offered in UK - 4Car News from Channel 4
Specialist firm GoinGreen is offering Prius owners this modification from September 2006, though a small number of advance examples will be available from April. The conversion adds batteries to supplement the Prius's limited range in electric-only mode; these can be charged by simply hooking up to a conventional electric socket. . . It's not cheap, though; the conversion currently costs £12,700 plus VAT - and the cost of the Prius in the first place - though this will come down to £7,700 plus VAT from September.