How about taking a beach photo with your flip flops, your wife's flip flops, and a tiny baby pair of flip flops all lined up together in a row in the sand, and then write the due date in the sand? :-)
I love this idea... you could also do it with bare feet... but then you'd have to borrow someone's baby for the
Best wishes to the new family to be!
And next to the little feet in quotations you could write "soon come" and put the month baby is due!