It's not even that hard, I managed to design a simple PCB after only a few months of tinkering with hardware. It's really not bad, and very fun. I recommend it to everyone.
I enjoy PCB design too - through it results in me spending an inordinate amount of time tweaking trace placement and ground planes for mostly aesthetic purposes :)
For one-offs you can entirely forgo the PCB design if you so desire as well and just use the PCB stock and rats nest it.
One of my creations: http://imgur.com/mcS79lU - fugly but very robust, functional, free of nasty parasitics and from paper to powered up and working is around 20 minutes work.
