I visited the site below and found some really simple, and fun activities to do with your classroom or at home! I remember how excited my preschoolers were when the "Leprechaun" visited the classroom... Its pretty magical for them!
http://www.perpetualpreschool.com/holiday_themes/stpat_games.html
For St. Patrick's Day: Fill a black pot (I use a Halloween witch's cauldron) with either gold foil covered chocolates that look like coins, or gold foil wrapped Hershey's HUGS. To make the pot look really full, stuff the bottom of the pot with crumpled newspaper and cover that with a piece of black construction paper. Show the pot of gold to the children in the beginning of their session, then, when the class is out of the room, ask a co-worker to hide all the "gold" and turn the pot upside down in the center of the room. Have a note written on the chalkboard (in green chalk of course!) that reads: "Have some fun and find my gold". Explain to the class that leprechauns are full of fun and mischief and that they want to play a game! Find the hidden "gold" pieces and count them. You can use both types of candy for this activity and then do a sorting activity. Let each child take home one or two pieces of "gold". My class loved this activity.
Leprechaun, Leprechaun Where's your shamrock?
This game is a take off on "Doggy, Doggy, Where's Your Bone".
The "leprechaun' sits with his eyes closed and a paper shamrock behind him. A child is chosen to tiptoe up and take the shamrock and return to his seat. Then all the children hide their hands in their pockets or behind their backs and recite "Leprechaun, Leprechaun, where's your shamrock? Someone has it in their pocket!" The leprechaun gets 3 guesses as to who has his shamrock. The person with the shamrock is the next leprechaun. My 4's love the versions of this game.
Place three plastic shamrocks (break off tips from those plastic cupcake decorative sticks you can find at the cake decorating store) into a bowl of green rice (color with alchohol as above). I also provide a pair of children's sunglasses with the lenses covered with green felt as a blindfold. The child tries to locate the shamrocks in the rice without the use of sight.
Leprechaun Gold Game
I spray paint macaroni with gold paint and then hide them in the rice/bean table. They children are convinced the leprechaun lost his gold. They love finding the gold.
We had such a nice weather day today... I broke out the new bubbles I bought. The small bubble holders run out so fast. Not to mention "accidental dumping!" Then I remembered how easy home made solutions are to make. They are great to have on hand when the bubble holders get low. Just fill um up! 
