In reply to GridNorth:
> The Trango one doesn't have a handle or shoulder strap though, does it? I want something that I take out at the crag and use to carry the rope between routes without having to pack it away in the rucksack.
No, it has neither, but if you just grab the 4 corners of the tarp, it lifts fine and is no trouble to carry. Going any great distance and you'd probably be taking your rucksack too, so can just shove it back in there.
Decathlon do a small, courier-style Simond bag. I've not seen one in the flesh (just their larger, circular one which is excellent due to the perimeter draw-string & handles on the tarp) but it might be worth checking out:
http://www.decathlon.co.uk/simond-rope-bag-id_8173554.html