I'll give you the definitive answer on this as I have a professional interest.
If you mean the I-Plate then this is well worth trying. The device replaces the front plate on your master socket and incorporates a broadband filter at the earliest point in your domestic wiring. Not all master sockets are compatible but a quick google will sort you out.
There are other ways to boost your speed. Disconnect your bell-wire as mentioned by Green Granite however I can't remember the pin connection, it may well be #3 but google it. Connect your wireless broadband hub directly to the I-Plate. All internal extensions kill broadband speeds unless you have a decent quality twisted pair. The cheap stuff bought in Maplins, Tandy etc. is only fit for phones. Give your local exchange time to adjust to your new set up and the DSLAM will re-set to the new (hopefully better) speed after 48hrs.
I had 2 broadband lines at Chez F with one running at 7 Mb and the other giving a p*ss poor 400k. Both were served by the same cable however the slow one was routed around some very dodgy internal wiring. After doing all of the above, it rarely drops below 6.5 Mb. I'm not even in the same county as the serving exchange !!!!!
If you do all of the above and don't get a decent service after a week, drop me a PM.