Well looks like Ofcom is getting things sorted out for these devices now.
From the 8th of December short range personal radio transmitters like the iTrip will no longer be illegal.
You also will not need a licence for citizens band radio anymore.
Though there is a slight wrinkle
From the BBC
From the 8th of December short range personal radio transmitters like the iTrip will no longer be illegal.
You also will not need a licence for citizens band radio anymore.
Though there is a slight wrinkle
However, many devices currently on the market will remain illegal as they do not meet the legally required technical specifications and could interfere with radio broadcasts.
The new amendments will also reflect a European standard on the low-power transmitters.
All approved transmitters will carry a CE mark indicating approval for sale in the European Union.
From the BBC