Sounds like a good idea for smaller purchases, but for big purchases I prefer to consider any interest I might be be saving by keeping the funds in the bank for as long as possible.

Not a huge purchase per se, but we mostly paid for a cruise once with a coin bank inside our front door. It ended up a large (a few feet tall) plastic bottle. I can't remember how long it stayed there.

Each time we came home we would empty our pockets into it. Of course thousands of dollars of coin can be a little intimidating -- we ended up taking several trips to one of those coin counting machines to take care of it all.

We, especially me(I?), don't do cruises any more. I don't like the way they treat their people. But that was a good one -- a front-corner cabin on the second trip of a new at the time Royal Caribbean ship with a picked crew (they considered it a reward). Our cabin steward had brought her husband with her as a small vacation of their own. We met some great people.

We helped one ~30-year old woman with her father and their packages ("But you guys are nice. Americans are never nice." ) in Puerto Rico. She was from Mexico City with her extended family. Her older father had paid for their trip. But since she didn't have any kids she spent most of her time taking care of him. He ran a gambling house where she grew up and she had some fascinating stories.