Ah, yes, those are sometimes used for retrofit jobs here. I've seen them used at an underground railway station where they obviously didn't want to bust up the walls but were forced to put up exit signs. Maybe they also already knew they were going to close down the station in a couple of years and didn't want to put in any money (I think it's going to be closed in 2009 or 2010).
I think I haven't seen any incandescent exit signs newer than some 50 years here... all newer ones are fluorescent, usually one 8W compact fluorescent, older ones mostly with a small battery, power supply and charger inside, newer ones in large buildings tend to be/have to be on a central battery, depends on the size of the bldg.).
3 years ago I did an internship with an electrical company and one of my jobs was running around in the garage of Vienna's court house and prison changing out old exit signs "because the batteries had failed". They claimed they had a power outage some weeks ago and the signs barely lasted 5 minutes. We used a couple of them as portable work lights and 4 hours later they were still going strong... whatever.
