As I don't have any Irish in me, I never think to post projects specifically to celebrate St. Patrick's Day. A visit to Michael's Craft Shop reminded me that it will be in a couple of weeks. Here's a few sites to visit with some patterns / projects / inspiration. You never know what you might find!
Q is for Quilter has some vintage shamrock quilt patterns
With heart and Hands - lots of freebies on this site - worth a look!
Quilt Inspiration - check out the free pattern archive
Pinterest St. Patrick's Day Crafts and Recipes
Needlework at Craft Gossip
Mini Shamrock Banner
A Quilting Blog
St. Patrick's Day Embroidery
Knitted Shamrock by Clover
More knitting from Vickie Howell
Crochet Patterns from Grandmother's Pattern Book
Idea from Craftsy