[|kbn|]

Heres a couple of pics of my hdd cooler, done it slightly different to everyone else. I dont really think it would make much difference either way though as hdds dont make much heat. I only did it this way because materials were cheaper like this - total copper pipe used cost less than a quid - copper sheet would have cost me £10.
You can see in the pics the pipe goes inside the width of the hdd's so it doesnt use much more space in width but more in height instead. This should give me more room for foam on the outside to quiten the drives and also some can go between the drives and above and below them too. I know it looks rubbish thats why im going to put it in a aluminuim box (which I still have to make).

For cooling your psu make sure the waterblock and all the mosfets on it are isolated from each other. Quite a few psu's have live heatsinks and use mica shims to isolate them - sometimes there will always be a voltage because of induction, but no current so its safe.

the best thing I can think of for the mobos mosfets is to move the capacitors and maybe the coil out the way but I think they could also be affected by it and make it worse? de-soldering them should not be too difficult but much easyer than moving the mosfets (which would have been best, but they are hard to de-solder). Mosfets have a metal back which makes the back the best place to cool if you can unsolder them... (or cut them off and get replacements).
cooling the back of the mobo is not going to be much better although it has loads of traces its also a good insulator (but it could be done using thermal tape to stop it shorting the back of the board).