I got this idea from a JHS teacher (learned a lot from her) and Japan's "business card culture" (not sure how else to put it).
First, print off and cut out the business cards.
Make “business cards.” Let the students draw a self-portrait and food, animals, or sports they like on the cards. Students should write their names in hiragana (kanji's hard on us ALTs). (5 minutes)
While the students are writing and drawing, write "Hello. I'm ____." and "Thank you!" on the board. With your HRT, demonstrate exchanging the business cards.
The students will exchange their business cards. They get to pretend to be each other. Let them exchange cards for 5 to 7 minutes. When time is up, the students should return the cards to their original owner.
Pro-tip: make your own card before class to participate in the activity with the students. The students really enjoy being sensei, even if it is just for a few seconds.