"Twas brillig, and the slithy toves
Did gyre and gimble in the wabe;
All mimsy were the borogoves,
And the mome raths outgrabe."
at a basic level, you could look at this to teach grammar rules. eg what are the main verbs, identify all the nouns etc
or to teach comprehension - eg how are the borogroves, what do the mome raths do.
i've also used it in "introduction to langauge" to look at how meaning is deduced, and the difference between understanding something and simply repeating back (what and how questions)
i'm sure this activity could be adapted for ESOL in some way.