Try this: http://ukcreditcardsdirectory.co.uk/ Also, look on http://www.cardweb.com they used to list a lot of cards for countries other than US. Might try yahoo's UK listings too. It's hard for us to search from a US ISP, because most banks will detect where we are and redirect to their US site.
Citi now owns Associates - Associates issues cards to people with credit problems - there is a link to the Associates UK site from the site I gave in my previous post. A lot of the major card companies will offer you a secured card if they cannot issue you a standard card for some reason, but they don't advertise their secured cards.