Accommodation
Mandatory picture of Big Ben © Ben Stafford, 2006
Hostels
Traditional youth hostels are run in England and Wales by the Youth Hostel Association, and in Scotland by Scottish Youth Hostel Association, both of which are parts of the Hostelling International network. These will provide basic clean accommodation. If lock-outs, curfews, school parties and rules are your kind of thing you are likely to find them perfect. In all fairness the best of them can be pretty welcoming to all kinds of guest, but ultimately their mission is still mostly to provide a wholesome and safe environment for teenagers, so don't bank on a party atmosphere and big groups of like-minded backpackers.
Luckily all of the more popular tourist destinations, such as London, Brighton, Edinburgh and York, and most other major cities, have at least one backpackers hostel. As these are independently-run, quality can vary widely from one hostel to another. See sections on the various regions and cities for hostel recommendations and links to booking services.