Here is an April Fools trick you might want to try on your families. It's from Martha Steward and it's called solid milk. It takes a few hours to do, so you might want to start planning today.
For all the details go to http://www.marthastewart.com/goodthings/april-fools-trick-solid-milk?autonomy_kw=april%20fools&rsc=header_7&xsc=eml_crd_2009_03_31