Capital One are offering a 0% Balance Transfer rate at the minute for about 11 months with a 1.7 % Transer fee (I think) which is quite good.
The way I calculate the different options to compare is like so:
If the credit card company offer you 0% on Balance Transfers for 11 months with a 1.7% and you transferred a balance of £2000 onto that card you would pay £34 as a balance transfer fee. - (1.7% of £2000 = £34)
however compare this with
If you take the example that a Credit Card charges you say 15.9% APR (Annual Percentage Rate) and divide this by 12 months (to calculate monthly interest) @ 1.33% and you had a balance of £2000 (which would normally reduce each month therefore reducing the interest but for this example we'll pretend the balence doesn't reduce) you would be paying £292.60 in interest over 11 months. - (1.33% of £2000 = £26.60 x 11 = £292.60)
So as you can see transferring a balance off of a card charging you 15.9% APR to a card which gives you 0% for 11 months with a 1.7% fee can save you nearly £258.60 over 11 months.
I hope the above info is actually correct but if somebody calculates it differently then please feel free to explain why cause I'm no expert on the matter.