So...that is where the fabulous Vistaprint comes in. This year I got smart and used the coupon they have for 100 free postcards to make my own personalized "Welcome to Kindergarten" postcards complete with a message from me on the back (you still have to pay for shipping which is a few dollars). They just arrived in the mail today and I am beyond excited-they are just too cute! Now I just have to print some address labels, stick a stamp on them, and they are ready to go!
I think the best part might be that since 100 postcards come in the pack, I'll have enough to use for at least 2 years. One less thing I'll need to think about next year!