Uncle DaveO, another good teaching example- These are my favorite flowers: violets, for their sentimentality; roses, for their color; and buttercups, for their cheerfulness.
On the other hand, this advice to writers from author Cornelia Evans: "If a writer wishes to use an informal narrative style he should avoid semicolons as much as possible. Semicolons denote a longer break in the sentence than commas and they may slow down the reader unnecessarily."