An alternative, and maybe more useful, would be the Garmin Streetpilot I3 GPS unit (reviewed here) -
http://www.gpsinformation.org/i3/i3.html.
Couple this with the speed camera site info files available here -
http://www.pocketgpsworld.com/module...eferer=SideBar and you have speed camera warning, plus a pretty decent GPS routing facility for about the same price.
Mine was £100 from Comet a year ago. However they don't seem to stock it now so it may be hard to find.