see kate sew: belly + baby // ruffled belly band tutorial --- Great, simple idea. Maybe someday, God willing.
VERY SHANNON: maternity sewing tutorial roundup this site has links to all sorts of tutorials that convert regular clothes to maternity clothes. There are pants, skirts, and tops.
luvinthemommyhood: Maternity Sewing Tutorials Roundup 2011 The mother of all maternity DIY. so many links.