If it's GPS-based then I'm guessing it must use a static database, which
requires connecting to your PC or something to get updates from the
internet? So, it's not really a 'detector', more of an 'alerter'. Correct me
if I'm wrong.
You could buy a PDA and TomTom5 (albeit, probably a dodgy copy) for about
Ł180 if you shop around. You then get Sat-Nav/Speed Cams/Other POI's, *and*
a PDA for your money.
I recently put together the above for Ł107.