Thanks all. I dunno about those Schwalbes - I've just had a look on the walls and there's no model name. I know they're current though because I cleared out the last of my LBS's stock and they got some more in, god bless 'em.
They had those in the Leeds Evans last time I looked!
On my Dawes I run gumwall Schwalbe Delta Cruisers. They have a nicer looking tread, are still cheap (a tenner or so) and have a decent puncture guard. The Dawes covers a lot of miles in a lot of crap weather and sometimes I think I should just stick Marathons on to save the bother of cleaning the sidewalls back to tan colour!