...the pound (£) shops.
In Peckham:
http://londonist.com/2008/05/peckham_pound_b.php But beggars can't be choosers.
Or can they?
Personal note: This entry was made with the help of a Signalex USB computer mouse - complete with scroll-wheel - purchased for the princely sum of £1 earlier this week.
It might not be about to turn up on The Gadget Show any time soon, but it gets the job done...