Terminal Commands:

One webcam:

ffmpeg -f alsa -ac 2 -i hw:1,0 -f v4l2 -s 1280x720 -r 10 -i /dev/video1 -vcodec libx264 -pix_fmt yuv420p -preset ultrafast -r 25 -g 20 -b:v 2500k -codec:a libmp3lame -ar 44100 -threads 6 -b:a 11025 -bufsize 512k -f flv rtmp://a.rtmp.youtube.com/live2/YOURSTREAMNAMEHERE

Two webcam overlay:

ffmpeg -f alsa -ac 2 -i hw:1,0 -f v4l2 -s 1280x720 -r 10 -i /dev/video1 -f v4l2 -s 320x240 -r 10 -i /dev/video0 -filter_complex "[1:v]setpts=PTS-STARTPTS[bg]; [2:v]setpts=PTS-STARTPTS[fg]; [bg][fg]overlay=shortest=1 [out]" -map "[out]" -map 0:a -vcodec libx264 -pix_fmt yuv420p -preset veryfast -r 25 -g 20 -b:v 2500k -codec:a libmp3lame -ar 44100 -threads 6 -b:a 11025 -bufsize 512k -f flv rtmp://a.rtmp.youtube.com/live2/YOURSTREAMNAMEHERE

Works as of Nov. 21 2014, with 14.04. As seen here: www.oldhomehandy.com

If you don't have FFMPEG installed use Jon Severinsson's FFmpeg PPA:

sudo apt-add-repository ppa:jon-severinsson/ffmpeg
sudo apt-get update
sudo apt-get install ffmpeg