Last week when my daughter's developmental specialist came to the house, she dedicated a couple of minutes to showing my little one how to blow a kiss. My daughter watched with interest, but didn't really get it.
Over the past week we've been showing her by blowing her kisses and moving her hand in the same motions. Then in the last couple days she's started getting the hang of it. I can blow her a kiss and usually she smile and give me one back. This marks another important two way conversation taking place. Turn taking like this is good progress.
It's also pretty cute and helps me to avoid giving my daughter an actual kiss when she still has such terrible drooling problems! ;-)