I'm going to travel the USA this summer, spending a week camping and hiking in Yosemite but most of the time in hostels in cities (lucky sod I am). Just looking at rucksacks for the trip there is a huge price range with seemingly little difference between them (to my untrained eye) apart from a few marketing buzz words. I tempted to go for a £30 bag and if it's no good after the trip it'll still be worth the money. Just looking for some suggestions and experience, cos I have none.
In reply to tedswag: I recently bought the osprey exos 58 and so far its been a great pack, its more than 3 litres bigger than the last bag I used, a 55 litre (can't remember the brand) and probably on a par with most market 65l bags. It is incredibly light for it's size, well designed and seems very strong. You could do much worse than one of these. The only problem is the price tag, £125 online was the cheapest I could find.