Related to current jersey issues, I got some jerseys from the closet and found a tape measure and checked some dimensions. It's a bit iffy measuring the Roadskater jerseys because of the double seams on each size (but that's part of what makes them supersweet, right?) but I did my best. Blake thought this information might perhaps be useful to someone some day.
Green 2006 jersey size XL: about 24" across chest just below sleeves
Iris/violet 2007 jersey size XL: about 24"
Orange 2008 jersey size XL: almost 25"