While surfing the net today, I cam across this "Repeater Article" on http://w5crp.com.  I found the following paragraph should be read by lots of us ham operators. So, thumbs up to N5CRP. 

Sometimes we get carried away with our conversations and forget there may be other hams wanting to 'get in'.  Give this a read, then use the link provided below to read N5CRP's complete article.

"If you are listening to one of the repeaters and no one is talking, you can announce your presence by giving your call only, or giving your call plus “listening” or “monitoring”, plus you may add “on 06” or “on 88” or what ever repeater you are on. That way if someone is listening on a scanner, he will know where to find you. As an example you may say “ K5CNZ, listening 06”. Do not use “BREAK”. This is reserved for emergency traffic. If someone is carrying on a conversation and you want to get into the conversation or need to use the repeater urgently, simply give your call between transmissions. The hams using the repeater will usually let you in. It is always good courtesy to leave a second or two between transmissions. The repeaters have a courtesy tone; wait until it sounds and a second or so more. Don’t be a ”Quick Keyer”, allow other stations a chance to get in."

You can read the entire article HERE on N5CRP's web site.