I currently use my mobile phone contract for my internet at home too. Unlimited data package with average speed of 4.5mbps. Just use the phone as a wifi hotspot. Saved quite a bit from having a separate home internet land line. Was thinking along those lines, but looks like I too will have to adjust my data habits.
We will be renting a room off a very nice lady who doesn't have the internet in her house as she has a sim card for her i-Pad (other generic tablet computers are available) rather than a land line internet connection and as we are not entirely sure how long we are going to be living there we didn't want to commit to a land line fixed term contract. I have looked into buying a mobile WiFi hotspot, which I am guessing is just a router which uses a sim card for the connection, of which looks like a good option as we will be able to take that with us if we move.
I will just have to make use of freely available WiFi when I am out and about.