Computer Sites that Accept International CCs?

neves asks: "I'm a student from Brazil writing this with my four year old pentium 233Mhz machine. Tired of suffering, I had decided to upgrade my machine when a golden oportunity appears: a friend of mine is comming from California to Rio de Janeiro and has offered to bring some components! Computer components in the third world are twice the price, and a generation behind ones available in the US, so now it is possible to buy an Athlon 900Mhz, an Abit motherboard and a good fan for less than US$500,00. You'd think I would just have to order what I need from a web store and have it sent to her address in California, but this hasn't been that easy. I've been trying for weeks to find a trusted store that will accept my International credit card! I've already used it to buy gifts and from Amazon to send to friends in the US (but Amazon doesn't sell motherboards). I need this information fast, as my friend's due to travel soon." I would think, with the Internet doing it's thing to erase regional barriers, that online merchants would be interested in accepting more than just "VISA, Master Card or American Express," however this seems to make this assumption invalid. So why is it that they aren't able to accept payments from International Customers?