I'm building a computer for a friend who's a very heavy gamer but doesn't know much about the inner workings of computers and has a large amount of money to throw around. I haven't really been keeping up with all the newest parts but as a personal preference I like to stick with ATI and AMD. After looking around a bit we decided to wanted to go with a Phenom 9550 Black edition processor and a Radeon HD 4870 X2 for the build, and wanted to put in some DDR3 but so far I've been unable to find a motherboard supporting it.

So my question is: Are there any motherboards that support the AM2+ socket, DDR3, and Crossfire (for adding a second card later)?

Intel is licensed for Crossfire. For what you want to do you really need to look at Intel motherboards such as the Asus P5Q series and Gigabyte boards; there are tons out there supporting DDR3 and overclocking. AMD processors are not as fast as Intel's, so generally AMD is working harder for the server market.

AM2+ socket = DDR2 only, for DDR3 look for the AM3+ socket coming out sometime later this year or early next year. You can still get decent speeds out of DDR2 though. Look for an AM2+ board that supports DDR2 1066.

Don't push your misconceptions on your friend. Get DDR2 and a Q9XXX if he has the dough, or a Q6600 with a "free" OC to 3G/1333. It's $179.99 @ Newegg.

Having money is good, burning it is bad.

The irony is that intel chip performance is less sensitive to to memory speed then AMD's yet intel strikes first with DDR3 just as it did with DDR2

Yes. I was under the impression that the OP, Zyvorg, thought he HAD to get an AMD or ATI chipset to run Crossfire, whereas in fact Intel makes the most widely-adopted Crossfire platform. Nvidia cards are limited to the Nvidia chipset until the Intel X58.

With Quickpath that will change. For the Core2 it's definitely not worth the cash.