Combining that socket LGA 775 processor with DDR1 really limits your options for motherboards. There's the ASUS P5GPL-X SE that can accommodate both, that uses the Intel 915PL northbridge. It's inexpensive too. So when you are ready to upgrade to DDR2, replacing it won't be so painful financially.
Would ddr2 really help my performance in games with a 650 prescott?
I currently have 2gb ddr1 dual channel what if i got ddr2 igb what would be better?