I've seen a lot of posts with people talking about installing auxilary fuse bocks, mostly from Painless. I just wanted to share how I just installed an auxiliary fuse block will nearly unlimited potential and spent less than $30.
I picked up a fuse block (out of a 2001 Chevy Silverado), wired it to a terminal strip.
I found this fuse block on ebay for about $15 shipped, the terminal strip was about $8.
I used a continuity tester to map the block in order to properly wire it.
Currently, I've only made use of 10 of the 40+ available circuits and haven't even started adding relays yet (it has room for about 11 relays).
You can see below how it's set up under the hood.. though theoretically you could locate it anywhere. This particular block is a little large, but once I moved the coil it fit snuggly in the corner.

 

Heck yeah, thats a good deal. Never really thought about doing something like that. I'll have to remember that one. You could also locate it in cab, to help keep dirt, water & more from getting to it.

 

The cab was my first thought too, I may put a smaller one in there later.
I just wanted something to better organize all my circuits.
I was having trouble with my rear window so I pulled out the factory control box, tossed a couple of my own relays in, provided power from that fuse block and hooked the switch up. Now I can even role my window up with the runner off!
Anyways, I also forgot to mention that that fuse block came loaded with fuses and relays. The fuses alone were worth $15.

 

Good idea, I like it even simpler where you just use a small plain jane fuseblock and you wire in everything the way you want it.