I didn't find a lot of classroom ideas when I did a quick Pinterest search but there are a lot of party ideas involving Smurfs. But you could use the Smurf pictures as accents around your room.
For instance...white bulletin boards with blue borders with Smurfs as accent pieces? Or a print out of your class rules with a Smurf picture.
I remember watching the Smurfs when I was a kid and I thought they said things with Smurf in it...like "have a Smurfy day!". Maybe you could "smurf up" some of your classroom signs.
Like...Smurfs RULE! (for your classroom rules).