How do you work out which is your exchange ? I have 4 around me so is it which is closest (all look about same tbh) 1 says opening soon, 1 taking orders & 2 future. All are quite far though.
In order to find your exchange you go to
http://www.samknows.com/
Look on the right hand side and click 'UK Broadband Availability'
This will open up a drop down, then click 'Exchange Search'.
Type in your postcode, and it will tell you what exchange your on
Click the exchange name and it brings up the details of what equipment is in your exchange, and which carriers are available.
Remember BT Infinity is a product name, the technology is called FTTC (fibre to the cabinet). BT are just one of many companies who offer this product. You do not have to take it from BT, their pricing at the moment is pretty good, but they aren't always the most competitive. Also if you use torrents, be aware they throttle P2P traffic between the hours of 8am and 12am, so all of the way through the day basically.
The markers your looking or are:
ADSL = Basic 2 meg Broadband
ADSL max = 8 meg Broadband
SDSL = Only relevant to businesses and a dying product, for the most part it's 1.5 to 2.5 meg in both directions
21CN = 20 meg broadband for everyone
LLU = 20 meg broadband from any of the companies listed on the right hand side, excluding BT. LLU means local loop unbundling, and it's where a company like Sky or TalkTalk put their own DSLAM (the kit that facilitates broadband) in the exchange.
FTTC = 40 meg/ 80meg/ 0r 160 meg broadband. Note, unlike normal ADSL that runs over coper (FTTC is still ADSL by the way), your speed will depend on your distance from the Cabinet, and not the exchange. The use of fibre to the cabinet, overcomes the the problems with distance from the exchange.
If Virgin is avaiable in your area, then it can be a good alternative if you can't et FTTC. You'll pay for the increased speed though and Virgin are fickle about P2P sharing, and possibly other things as well. I'm not sure if they allow proxy's or block filehosting sites that are listed on Warez groups (rapidshare/ netload/ filefactory etc).
Hope that helps.