Simply reply and...

1. I'll respond with something random about you.
2. I'll tell you what song/movie reminds me of you.
3. I'll tell you my first memory of you.
4. I'll tell you my favorite memory of/with you.
5. I'll say something that only makes sense to you and me.
6. I'll tell you what animal you remind me of.
7. I'll ask you something that I've always wondered about you.
8. If I do this for you, you must post this on your journal.