Many people have had questions about how to make improvements to their computers so that Battlefield 2 will run better. Corsair has produced a document that just may answer that question by detailing how performance improves when you upgrade from 1 GByte of ram to 2 GByte for a variety of applications, including BF2. This improvement happens regardless of cpu platform or screen resolution which indicates that for your dollar, it is apt to be a better alternative than an upgraded processor or video card.

Read the document here (pdf): Performance Impact of Changing Memory Size from 1 GByte to 2 GByte

Thanks to Zardon at Driverheaven for posting the link originally.