My little gift has been identified!
A friend posted a picture of the plant on a gardening forum and sure enough, someone knew what it is! (Aren't forums/on-line communities/bulletin boards such a great resource?)
So, without further ado...
The plant is a Dischidia pectinoides (dis-KID-ee-uh pek-tin-OY-deez). Its common name is Kangaroo Pocket or Ant Plant. After reading the care & feeding instructions I am doing just about everything right, except that I should feed it occasionally. The bonus is, if I do that, it should bloom year round!
It seems that planting in shells is the common as seen in this picture from an exotic plant sale.
Janice, thank you so much for finding the information!