I have been a guest designer for quite a few different challenge blogs.
February 2012 - Sweet Stampin' challenge
February 2012 - Sweet Stampin' challenge
January 2011 - Quirky Crafts challenge
September 2010 - By the Cute & Girly challenge
June 2010 - Digi Doodle challenge
June 2010 - Stamptacular challenge
April 2010 - Raise the Bar challenge
March 2010 - Stampavie & More challenge
Guest designer for Dies to Die For
I was also a designer for Susie's Sassy challenge (but unfortunately the challenge blog closed)
