I believe that I'll be taking Shakespeare's
Sonnet 116 ("Let me not to the marriage of true minds"), which I've been working on memorizing off and on for a while now.
If you're inclined to want to take a poem along in your pocket tomorrow and don't have one selected, consider visiting
The Academy of American Poets' pocket poem page, where you can pick a topic and find a poem. (I'm partial to "Roses" and "Gyre", but you may prefer something else.)