Very good article in the Guardian today, which is well worth a read ... its about 'ethical banking' - but don't be put off, it is an interesting read!
... I should declare my slight-bias here - I switched to the Co-operative Bank years ago, and I also use the local Credit Union for small savings and loans (which I frequently need!), and I've had nothing but excellent service from both organisations over the years I've been a member.
I do think Deborah Hargreaves makes some very telling points about the banking industry having to rebuild faith amongst its customers (very similar points can be made about politics in general) and models such as the Co-operative Bank and Credit Unions could well provide a few lessons on how to do just that.