I think that you will find a great deal on Moneysupermarket.com thats where I got my travel insurance, and they actually had to pay out on my policy as I ended up in a French hospital.

My insurance was about 40pounds, and it was for annual insurance! I think from memory you could go away for up to 94 days at a time, or 17days at a time if you included winter sports.

Hope this helps - just remember to read the small print about how many consecutive days away from the UK you are covered for! Happy Travels!