Re: How can you boost a guitar?
Moving your pickups closer to the strings increases output a bit more, but you can always just shove a booster unit into your guitar. If you're good with a soldering iron and simple electronics, you can build your own mini booster unit. (you can also get higher output pickups like an Air Zone or Tone Zone)
Personally, I would still use a Tubescreamer, SD-1 or some other overdrive pedal into the frontend of my amp. Do note that you can usually mod a cheap distortion/overdrive pedal into a clean(er) boost pedal but swapping out the diodes.