Continuous dial/potentiometers for OBS/HSI control?

Hi,

I've been searching around but haven't really been able to answer my question:

What's the best way (assuming there IS one) to build a small generic continuous rotary control? Basically, as noted, it's for rotating things like the OBS or indicators on an HSI... stuff like that.

Like the real wold units, they need to be able to be rotated continuously in either direction.

Also - using SPAD to get the Saitek radios undercontrol is working so far; is this the same type of solution I might use for the dials?

thanks,

Andrew