For British savers, here is the current position:
"Financial Services Compensation Scheme
The Financial Services Compensation Scheme (FSCS) was created and put into operation in December 2001. It was brought in to replace the Building Societies Investor Protection Scheme, Deposit Protection Scheme and several other schemes previously in place. The FSCS was introduced to protect customers of firms that go into liquidation or out of business.
The scheme is activated when an authorised firm goes out of business or the Financial Services Authority (FSA) considers that an authorised firm is unable or unlikely to be able to repay their customers.
Most customers are partially protected under this scheme and are entitled to the following amount of compensation:
100% of the first £2,000
90% of the next £33,000
The compensation limit applies to individuals and covers the total amount of all their deposits held with that firm. Each individual in a joint account is eligible to receive compensation up to the maximum limit in respect of his or her share of the deposit. The FSCS assumes the account is equal and splits it 50:50 unless evidence shows otherwise.”
Source: http://www.moneysupermarket.com/savings/GuideToSavings.asp (accessed 17 Aug 07)
From this you can see that for your savings lodged with any one deposit taker, any excess over £35,000 for a single account holder, or £70,000 for joint (50:50) holders, is not protected.
Some may say, "It can't happen here", but it did in the Isle of Man in 1982, where the Savings & Investment Bank collapsed, losing £42 million of depositors' money. International bank BCCI collapsed in 1991 with debts of £10 billion, hitting 6,500 British depositors - and the legal case against the bank ultimately collapsed as well.
Savings schemes are not safe, either. About £41 million was lost in the Farepak Christmas hamper collapse last year.
The strategy is to know your rights, and to diversify. As Antonio says in The Merchant of Venice:
My ventures are not in one bottom [i.e. ship's keel] trusted,
Nor to one place; nor is my whole estate
Upon the fortune of this present year:
Therefore my merchandise makes me not sad.