It's tougher on the body but I stand. Using wireless Headset mic and wireless acoustic guitar switching back and forth depending upon the song. I also find that standing allows me to sing better and on tunes where I am playing guitar I can get up close and mingle with the audience and dance/sing with them.
Losing about 40 pounds has made standing easier too! Whatever works for you.
Brian
I sit when I practice and stand when I perform. It does help with singing to stand - but to each they're own.
I would like to explore the way the Yamaha Super Articulation voices respond to the footswitch, but I would have to use my left foot (I use the right two footswitches for sustain and fill-to-self) which is difficult when standing.
There has been a lot of news lately about the dangers of sitting too long:
http://www.nytimes.com/2010/01/26/health/26beha.htmlBeakybird