5 years in writing (see bottom of page), ARP has now released the latest version of their Virtual Memory Optimization Guide (version 4.1)

Since hard disk is WAY slower than RAM, increasing virtual memory / swap performance will always give you instant increase in overall system performance.

Of particular interest would be movingswap file to outer tracks (max 200% performance gain), create multiple swap file on different hard disks (just make sure to read this as well), and stopping Windows from paging itself to disk.

A recommended read.