The Ethics of Usury

Against the background of the current financial crisis and astonishing levels of personal debt, it would be impossible to argue that the practice of lending and borrowing money at interest is always morally acceptable.
 
Is the biblical answer simply to say "No" to the practice of lending and borrowing money at interest? It would be fair to say that for the major part of church history the mainstream view has been strongly against it. However, something has clearly changed. Christians today happily take out mortgages and keep their money in banks which then lend at interest to others. Christians may even personally profit from the lending of money at interest.
 
Is this change of attitude a humane ethical evolution, regardless of what the Scriptures say? And, if so, can the same principle then be applied to other ethical issues? Or should we attack the contemporary moral laxity of Christians on this issue, and call for a return to the prohibition?
 
Or might there be a different answer?