There's one along Embankment in London today, as you head west.
Just after the tunnel that everyone bombs through at 45 ina 30 limit, which is just after the gatso in the 30 limit, which is just after the pointless 20 limit with SPECS cameras.
Saw it as I cam out of the tunnel (first mobile I've ever seen) and thought - that looks like a gatso on a little tripod... right next to the white van... and braaaaake.
It's a bit scabby though, how many cars must get busted in the SPECS area, then once they pass the gatso they speed up, glad that they can once again get on with their journey, only to get snapped again.
That'll be £120 and 6 points today pur-lease!
On the plus side, the SPECS area can't do bikes, and has these great digital readouts that tell you your speed (i.e. tell you how fast you are if over the 20 limit) - I managed to get 23.4 within a few metres of launching from a red light - great fun... will have to try and beat my score as the weeks progress. I'm sure I've heard of people getting a score of 30 or more