Rather than buy an I Plate you can just disconnect the bell wire. Easy enough see a good guide at:
http://broadband-speedup.blogspot.com/
or google for more...

I have been complaining for 2 years now to my ISP (Karoo) about measly speeds. I suggested to their customer services and tech support that I believe I should have an NTE5 fitted as all I have is the very old master socket (early 70's) I was "informed" that this would make no difference to my speeds. Only after being on the phone for 1hr did the guy (who to be fair at least investigated the data) say that I should have an NTE5 fitted first, so presto, they are to fit one monday. Hopefully my speeds will increase accordingly!

proper link here...
http://www.thinkbroadband.com/news/3725-final-full-launch-of-bt-wholesale-i-plate.html

I would not call a faceplate a gadget.. AFAIK all it does ids disconnect the ring wire.. For the daring, here is how to cut it...
http://www.thinkbroadband.com/faq/sections/radsl.html#235

and how to fit an ADSL faceplate..
http://www.thinkbroadband.com/faq/sections/install.html#226

get them here...
http://www.adslnation.com/products/xte2005.php

http://www.solwise.co.uk/adsl_splitters.htm

ADSLNation have had a faceplate out for ages. The XTE-2005

http://www.adslnation.com/phpapps/catalog/product_info.php?products_id=105

I got a 2.5Mbps increase when I installed mine

they are already up on the bay and I have on one its way...

I'll post back here if it helps at all.

You know what Karoo in Hull don't believe these work as they stopped selling them because they say there was no gain. They continue to install 2 blocks for phone lines because it was cheaper I managed to argue to get them to change it to 1 newer block if I can fit this I am going to buy it for sure.

Karoo at that good there techies didn't even know about the Zone Alarm firewall fiasco with that Microsoft Patch I had to tell them about it and even tell them ZA released a new version that fixes it.

This story was a bit thin on the details and confusing since ADSL already uses filters so I googled and found this to be what it is for:

"The imbalance and noise pick-up due to the ring wire used in phone wiring in the home in the UK has been known about for some time. In the past the solutions have been to fit an ADSL faceplate to the master socket, or manually remove the ring wire."
source:
http://www.thinkbroadband.com/news/3461-new-tool-on-its-way-to-bt-wholesale-armoury.html