but can it tell if a cd is a 1:1 copy- no so its useless

pcshateme,
might be you just have not fased with audio CDs, made from MP3 and sold to you as brand new originals.
Such a discs have different quility of sound but 1:1 copies have the same quility.
In my collection now approx. 25% of CDs made from MP3, as i now know, so such a detection is pretty usefull, especially in some countries :)
Best Regards,
Oleg.

yeah i guess in china it could be pretty useful :)

How useless is this? Either you cart a laptop around the stalls and markets of Taiwan, Singapore, &c, and demand vendors open the packet so you can test the CD - in which case they'll tell you where you can jam it. Or you can test the CD when you get home to civilised parts. And what are you going to do then if it's pirated? Hop on a plane and demand a refund? I suppose you could write strong letter to the market holder demanding a refund and see what happens.

Could be very useful for a retailer, to make sure that his suppliers aren't ripping him off.