They are 1/4" id poly tubing from Home Depot. I started with 10 feet, but was having foaming issues, so I went up to 25' per line. I run around 8-12 psi.
I'm still having foaming issues now, but I've tracked it down to my freezer being 15-20 degrees difference from top to bottom, so all of the co2 is coming out of suspension just before the taps. probably what my issue was before, but I don't feel like taking it all back out now.
Don't know why the photos aren't showing up, they're on my album here.