In reply to Matt250:
Patagonia RPS pants (yes thats trousers to us).
Lightweight comfy and super hardwearing for their lightness...smart looking too.
i bought a pair initially at full price and like them so much i bought a second pair at full price...almost 3 years on and they are worn almost daily...casually, walking, scrambling and climbing. Both pairs showing very little sign of wear. Best trousers i have owned. Good in heat but surprisingly wind cutting if its cooler too.
highly recommended.