A classic element of office humor in English-speaking nations, a "round tuit" is both an object and a pun at once. It is common in these countries to apathetically state that one will do something when one gets "around to it". Hence, the "round tuit". If you were putting something off until you get around to it, someone may just give you one and remove your excuse.
Assorted pieces of humor on the subject abound. It is relatively trivial to find a place which sells "round tuits" which are commonly pin-on buttons, wooden tokens, or round pieces of paper with some presumably humorous statement on them about your new posession of a round tuit enabling you to perform all of those tasks you have been putting off until you get one. It has become something of a staple of low-grade internet humor, but the meme populated itself rather efficiently from office to office ("when I get around to it" is a phrase commonly heard in the working world) before the widespread adoption of the 'net via fax machine.