I use a santander free business account, they automatically open an instant access savings account that runs alongside your business current account, just transfer some into the savings account each month. It doesn't pay great interest till you have over 10k in it (in fact its still not great even now that I have over that) but I would rather have it in my account than the tax mans.
As long as you dont mind only having use of machines and internet to do your banking its great. I thought it might not be when I first opened it, but now I have got familiar with it, I really like it, and I work just by a machine every friday so its very handy.