To start off with DDR2-667 memory, Newegg currently sells this 2GB kit of OCZ Value Series DDR2-667 memory for a cool $61.99. If you're willing to go for a lesser-known brand in order to save a few bucks, Newegg also offers a 2GB kit of Wintec DDR2-667 RAM for $59.99 with free shipping. Both the OCZ and Wintec kits have lifetime warranty coverage.
Moving on to DDR2-800, for which some folks might be inclined to pay extra cash, we've spotted this PQI Turbo 2GB DDR2-800 memory kit also at Newegg. This particular offering is on sale for $85.99 with free shipping, and Newegg even offers a $15 mail-in rebate that can squeeze its price down to just $70.99. That's $1 more than the 2GB DDR2-667 kit we selected last week, and this PQI set is rated for operation at 800MHz with 5-5-5-15 timings and a voltage setting of 2V. Lifetime warranty coverage is on the menu, too.