For what? BT, your internet connection itself or what? If you using DSL i've read somewhere that you can speed up you connection simply by upgrading your filter. You can modify your modem or router's internal settings, software, firmware, and sometimes hardware for some improved results.
I guess BT is a UK ISP? NanuGama, you'll have to upgrade your internet plan if you want to increase your upload speed. Who is your current ISP and what plan are you on?
I have Time Warner as well and I have the 15Mbps down and 2Mbps up plan. It's great, but I don't think they offer it in all areas. Do you know the speed of your current plan?
I think the max that Time Warner offers is 15Mbps, with a speed boost up to 32Mbps for the first 10MB of files. Charter Communications, however, offers up to 60Mbps in the US.