Core i7 is truly the way that the CPU market will be leaning over the next few months. While Core 2 will get a few refreshes, it's certain that Intel will soon ramp up with Core i7, introducing new models, higher clock speeds and inevitably better prices to make it more attractive.
Where Core i7 really gets a lot of its power from is the triple channel memory controller and while we have shown that even dual channel keeps it happy, there is no better feeling than stuffing it with more memory bandwidth than it knows what to do with. Having said that, A-DATA provides an extremely impressive kit here for your consideration.
Compared to the Corsair 6GB kit, while it's half the size, it's also cheaper. DDR3 still costs more than DDR2 but we soon hope to see this change. The other major advantage of this kit is that being only 3GB in size allows it to fit within the 32-bit OS usable memory window. 4GB and above needs a 64-bit OS to take advantage of any extra memory, so you're safe for XP and Vista 32-bit here.