When we did the Stewardship unit we made giving-saving-spending banks out of the small pringles potato chip cans. We decorated each can with paper cut to fit the can, then glued the new can covers on the cans and put a coin slot in the plastic lid. We hot glued the cans to each other using a rubberband to hold them in place while the hot glue set.
Update: In this day and age of debit cards and electronic payments, "loose change" isn't as easy to find in each home as it once was. But you can still use these banks to help spur discussion about "what to give" (and where to give it) by going on a "LOOSE CHANGE SCAVENGER HUNT" in the family car, purses, and all the places where parents toss their coins. To help make an impact, suggest parents convert dollars to coins and award for "doing chores" which their kids can then "spend-save-give" from.
To spur thinking about "what to give" and "how much" will be needed to give it, come up with a list of suggested "gifts" such as baby diapers and wipes, a case of ramen soup, a new pair of shoes, and hygiene supplies like soap and a toothbrush.
You can also take your student to the store and buy these things, then place them on the family table with a large price tag, and put a "GIVE" can next to it -- into which kids can put coins they have earned by doing various chores.