So I recently upgraded to 16gb of RAM for my system on black Friday. I know most people don't think this is necessary and I agree with you but I have been fiddling around with RAM disk as a scratch disk for photos and handbrake and it is fantastic. (This is what I am using http://members.fortunecity.com/ramdisk/RAMDisk/ramdiskent.htm)
Handbrake is where this really, really shines. I do a lot of bluray encoding (on an X6 1055T @3.75ghz) and I have seen a huge progression in encoding times from mechanical HDD to SSD to Ram Disk.
2 Hour BluRay (Iron Man 2)
Mechanical HDD (1TB WD Black) FPS avg: (18 peak, 10 avg) - completes in about 4-4.5 hours
SSD (kingston 128gb (I know its not the fastest)) - FPS avg: (25 peak, 17 avg) - completes in about 2.5-3 hours
RAM Disk - FPS avg: (43 peak, 32 avg) - completes in about 1.5 hours
I can't believe how much of a difference this makes. It is close to three times faster than a mechanical HDD and I am sure if I could put the entire file on the RAM disk rather than just running handbrake in the RAM disk and having it write the file to the SSD I am sure I could get rid of another bottleneck.
I am actually going to try it with a DVD and see how fast I can rip through with the whole file being on the RAM disk. I am hoping something like ten minutes.