Nowadays holy water is usually blessed at the Easter Vigil Mass and kept for use throughout the year in baptisms and blessings, including that self-blessing when you walk into a church. And while most people don't go about trying to cure diseases or grow the crops with doses of holy water, some people still gather the water in vials or flasks and keep it in their homes.
It also shows up in horror movies as a deterrent to vampires and zombies - apparently it burns the skin of the undead. So maybe keeping a vial of holy water in throwing distance of your front door wouldn't be such a bad idea - you know, just in case.
Read earlier installments of "Catholics Do This but Don't Do That":
#1 - Pray the Rosary
#3 - Genuflect
#4 - Confession
#5 - Vestments
#6 - Indulgences
#7 - Bible Books
#8 - Saints
#9 - Relics
Cynthia Stewart, a regular contributor to Patheos, has taught courses in the history of Christian thought, theology, philosophy, and medieval studies. She is the author of The Catholic Church: A Brief Popular History (St. Mary's Press, 2008).