Ahem, erm, well, yes. I sort of forgot, sorry.
Anywho here are a few pictures, bit rubbish but hopefully you get the gist of it.
I would do a drawing but the ones I tried weren't very good.
But the jist is the upper (facing PSU) and back sides are straight, the front side is bent inwards (20mm below the top) to meet the base and the lower side (facing the floor) is at an even steeper angle meeting the CPU coolers. The base of mine is 150mm long by 70mm wide. It also has a 10mm lip running round top and base to connect the fans and heatsink to.
As I said before the only issue with this design is that it covers the GFX card slots, making the AGP slot useless and the PCI-E slots only a little better. Thats why I stuck the 50mm spacer on the bottom, so there would be enough space to fit an AGP GFX card. The overall height (inc the spacer, funnel and 120mm fans) from the motherboard tray is 200mm. That doesn't bother me too much but could be an issue for others. The actual funnel though doesn't cover the second (lower) PCI-E slot (on the PCH-DL at least) so it would be usable with a proper card without the spacer. That would reduce the height to only 150mm, which would fit into any case.
Redesign it for 92mm fans instead and both PCI-E slots would be fine.
Anyway that is my very basic solution to the noise problem, it could probably be refined if I wanted to spend any more time on it but it was only a stop gap solution (on the very cheap) for a couple of weeks (so stop gap that the fans and funnel are attached to the HS by double sided sticky foamy stuff. It worked for my needs though so I can't complain.