of course, you can use something like the MB-2B Midboost/Fat Control Pedal from www.demeteramps.com
But I find it way more practical to have it installed in the guitar. Yes, it needs a 9v battery (lasts for about 1 year, and the guitar output won't be muted if the battery is dead)
Of course, if you use a lot of different guitars then it's more wise to go with a pedal.
I have really integrated this into my playing style now, and I could never get the same results from a pedal as I adjust the boost all the time, not just on/off.