dcseain | Request for Songs, Poems, & Sayings

A friend of mine teaches English as a Second Language in a prison.
He likes to start each class with an expression, quote or saying - not boring
proverbs that people don't really use in normal conversation, like 'So as ye
sow..,' or 'Spare the rod....' but fun things, preferably with plays on
words, like 'Time flies like an arrow, fruit flies like a banana,' or
'Outside of a dog, a book is man's best friend. Inside of a dog, it's too
dark to read.'

He ends each class with a poem or a song, something in real English, not
the textbook stuff for foreigners. He's used materials ranging from The
Prophet - On Children, to 'Boy Named Sue,' to 'Slow Down Krishna.' The
problem is that they have to be really simple, both in grammar and
vocabulary, and it's hard to find things like that.

So, he's running out of both. If some of you could post sayings, quotes,
expressions and/or suggestions for simple poems, He'd be really grateful (and
I think the prisoners would appreciate it, too). I'll pass on your suggestions
to him. Thank you!