I find it quite amusing to read posts like "not worth it". Considering the materials involved with ducting costs next to nothing, you're only going to spend some time.
Lately I've been using ducts to exhaust heat off the CPU, rather than just blow it around in the case. This technique lowers the temps of the PSU, the ram, the Northbridge...everything. It also then gives me the opportunity to lower the fan speeds, which makes the whole setup quieter.
Not worth it? Baa......
Here's another use for the
drier duct, which uses the PSU fan as the only exhaust fan, eliminates the CPU fan, and the rear case fan. Very quiet setup...