How Can I Make This More Obvious ?

I'm a talker.  Get me started and I can filibuster for hours (some say days, but let's be reasonable here people!)  It is just in my nature to have lots to say at any time.  I used to fret over this constantly.  It actually made the problem worse.  In my haste to say something with less words, I would feel the need to go back and fill in what I missed, which ended up taking even longer.

With that in mind, I am going to be blatantly hypocritical here.  I'm just mentioning that up front so no one can think I'm a talker and oblivious to my own hypocrisy.  :)

Why is it that some people just cannot take ANY hint that you try to give them when you just don't have time to listen to them right now?

I'd like to think that, while I talk a LOT, I am reasonably aware when someone doesn't have the time and I just need to go chat with someone else.  I try to pay attention to some of the more basic "I'm busy, can you come back another time" or "How long is this going to take?" signals that the average person just seems to know how to give:
 - tapping a pen or pencil
 - short or one-word responses (yeah, uh-huh, sure, hmmm)
 - multi-tasking right in front of you (checking email or the phone, etc.)
 - purposefully sounding distracted ('I'm sorry, what was that?' etc.)
 - looking at your watch or the clock on the wall
 - actually saying "Boy is it really that late already?!"

I have a few co-workers who just seem oblivious to these signals.  They are all great people and most of the time I enjoy spending 30-45 minutes conversing with them.  But sometimes, I only have so much time in that given day and it does not include any leeway for chit-chat.

Is there a better way, without being rude, to let someone know you just don't have time right now?  I could try to just say that very politely, but it never feels good.

Song Of The Day:
The often repeated line 'how am I going to get through?' is the reason I have chosen "What Have I Done To Deserve This?" by the Pet Shop Boys as the song for today.  I do NOT think I am being punished or anything by these non-readers of signals.  I just don't know how to get my message through to these individuals when I need to end our chit-chats.

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