has a number of different fan controllers. There are ones for individual fans, there are whole units for 3.5" bays, or PCI cards that utilize software (Windows only), and then there are 5.25" bay controllers... Which got me thinking!

I can get a controller that can handle 4 fans. Does anyone think it'd be too hard to fit one in if I were to remove the door of the lower optical drive bay in an MDD?

Here's a link to what they offer:

Alternatively, here's the one-at-a-time controller I was looking at, from the same place:
DP 1.08GHz PMG4 MDD, 1GB PC2700 DDR, 200GB ATA (16MB, 7200RPM), Radeon 9800 Pro (256MB)