wifi router and 3g

Hi,

Hope this has not been asked before..

This is probably a daft question, but I will ask anyway. I currently live in an area with a strong 3 (mobile network) signal and have a 'one plan' contract that allows tethering. I am receiving consistent speeds of 12-14Mbps? better than my historic adsl connection!!

Anyway, I appreciate you can get wifi routers that have the ability to connect to 3g using a phone sim, however does a device/process exists that would allow me to connect my phone (without taking the sim out) to a wifi router to allow all existing devices access to the internet?

I do use the phone as a hotspot, but I have multiple devices that have wired connections to my router. i.e pc, ps3, xbox360. I would rather not purchase wireless adaptors for all of my wired devices.

I just think I could remove the internet costs of fibre/adsl and phone line rental if I could come up with a solution.

Thanks for reading and any suggestions!!