If it's cold, take in some local architecture on a brisk walk. Check out your local art galleries, museums or exhibition halls for free events. Lunchtime concerts are becoming a very popular way to relax and forget your work worries. Check local press for details. For something spiritual, try yoga or meditation.
Most local churches are happy to welcome lunchtime visitors.
Credit cards are an easy way to deny what you are spending. When the bill arrives, check it for errors and then pay the whole balance. Never be tempted to only pay the minimum amount, as this is often only 3 per cent of the total debt. Look at how much interest you have paid in the last year - think what else you could have done with that money. Remember that if your store card has an interest rate of 28.5 per cent, over two and half years you will end up paying twice the original cost of the item.