Try your workflow. Human patience doesn't matter much when you're not patient to wait.
If, after upgrading RAM, your workflow is still too slow for you, either change your workflow (and possibly your applications) or upgrade your machine. Personally, I recently built a new machine, the important parts for photo editing being the 4-core CPU at 3ghz and 4gb RAM. This machine is significantly faster than the old mobile barton 2500+ @ 2.1ghz, 1gb RAM I was using previously.
My workflow as of late starts and ends with Lightroom. Lightroom isn't very friendly to slow machines. It also doesn't appear to be multithreaded, but I can run other photo-related threads while Lightroom does things like photo importing. Thankfully, the machine I have now works responsively enough for me when working with Lightroom.
