I'd always loved the following philosophical poem, which I read online many years ago:
I gave my love an emerose
Upon a summer day,
While all around us in the grove
The gavagai did play.
"I've never seen a hue so green,"
My love did say to me.
"My dear," I said, "it's shmolored gred,
Just green until time t."
Emeroses are emeralds until time t and roses afterwards. They're useful in setting up versions of Nelson Goodman's new problem of induction.
As I've just discovered, the poem was written by Brock from Battlepanda, back in his grad school days!