If you take quines away from computing for a second they become even more interesting. Good ol'Dougie Hofs gives a few examples in GEB, including:

"is made up of six words" is made up of six words.

Which is much more profound than it seems at first sight, and is a useful first step towards looking at self referential stuff like "this statement cannot be proven". It shows what the "this" is really doing, ie its inserting the reference to the rest of the sentence.