If you're of a mind to buy a round for a mate or one for the house, simply copy the URL address below (the one in red).
Go to the message board and at the bottom of the 'Post Message/Reply' form are three link fields.
Place the URL you copied into the blank 'Image URL' field and then type your message as you regularly would. Your 'round' will appear as an inset image at the top of the message you sent.
Have fun and remember to drink responsibly.