Can antone tell me please... if i`m from Europe and i want to buy an US Live card for 12 months...i know that you can email the code...and i have friends in the US,so... If i buy an US card will it work in Europe? If not,how could i make it work? To create an US account from Europe and then type the US code? Please help.

No.
It'll only work if you have an US 360 and if you live in the US.
You can only buy European Live Cards.
If it would have worked, I'd have use it too.

I`ve hoped that with an US account and card i could do it... how about with an US console in Europe? Has it been tried?

Well I've sold European cards on Ebay to people in USA/Canada and they worked so I don't see why not.

Poeple don't realise the old XBox live codes from the original Xbox are exactly the same as the new XBox360 cards, so stores sell the old starter pack off with the game and headset included for £2 and I resell on Ebay and get £30 for the included code

Unfortunately you don't see many of them now.

I`m not trying to make a profit by selling the codes from US to European gamers , but could it work? European 360`s with US code in europe or i need US 360`s ? 10x for responding,people!

Why do u want to buy a USA code if you live in Europe?

For the price. It`s very expensive here in UK,but in the US it`s at half the price (12 months of Live). So...does someone knows? And...where do i find 24£ -25£ codes,because i`ve seen only 39£  or more. Thanks again.

Plenty of sites out there sell 12 months for about £24/£25 if you search around.
No need to pay the extortionate price of £40 Gamestation / game etc charge.