in-line fanspeed control

[ZippyDan]

I have a miniITX system running as a server in a remote location. It has two 40mm fans that are pretty loud, both plugged into the mobo with 3-pin headers. I'd like to have them run at like half speed. The motherboard doesn't let me change the speed, and the OS is VMWare ESXi which also doesn't seem capable. There is no room inside the case for a fan control system. I'm pretty sure I could solder a resistor in-line to reduce their speed, but I'm not actually on-site. I want something that I can mail to this location and that even a noob could install - in other words something that will also plug into the 3-pin headers in-line with the fans.

Does anything like this exist?

Edit: Eh, found something on eBay. Nevermind