Masking shared internet connection

My girlfriend and I recently moved into an apartment which has a rather limited and rubbish internet service. It is wireless and only one device may connect from any account at any one time.

Given that we both have laptops, phones and I have a tablet, a kindle and three additional PCs this limitation is unacceptably restrictive especially as we are paying far above the usual market price for their 'Ultra Fast' 6 Mb/s service.

I contacted their support who suggested [without irony] that if we wished to connect multiple devices we could purchase extra broadband accounts, if we were to do so for each device this would amount to £270 a month.

I had initially tried connecting with one machine and enabling internet connection sharing via a second network interface but that hadn't worked.

Does anyone have any suggestions for circumventing this absurd rule?

if using windows connect one laptop to the wireless, then right click on the wireless adapter and go to properties and click "share this internet connection" then plug a wireless router's wan port into the laptop's ethernet
should work ive done this to make my htpc act as a "wifi booster"

Unfortunately as I said, internet connection sharing won't work. MAC spoofing had occurred to me too, but my guess is that two machines with the same MAC on the same network won't play nicely.

weird it should be showing all the traffic as the laptops though shouldn't be telling the network its giving it to something else, but idk i could be wrong.

Would a Thinstation setup work or would it show all the devices as separate macs to the outside world? I'm not too sure.
http://www.thinstation.org/
It requires one device running the thinstation iso as well as a separate server box.

You are looking for a device that does NAT. Basically, you need a wireless bridge (a router that can do DDWRT will work), which connects to their wireless and gives you an internal private network.

Thanks guys, I'll give it a shot later today.

EDIT: Thanks thideras, a DIR-615 running DDRWRT in Client Mode did the trick.

Awesome, glad it was something easy for you to setup.