Anyone who's a parent understands what the ten-thousanth "Mommy" of the day is like. When you have small children in the house, you're likely to hear "mommy" or "daddy" hundreds, if not millions, of times each day. You feel like you just might snap, go running for a one-bedroom effeciency in Kansas City if you hear it one more time.
Don't "Mommy" your reader to death, or move to Kansas City for that matter. (Although Kansas City is a fine place. Shout out to Gates BBQ. If you haven't tried it, start programming your GPS. http://www.gatesbbq.com/ )
When you're writing dialogue, keep the following points in mind:
1. Your characters are different. (At least they should be.) Gender, race, and personality all figure into how a person expresses him or herself. Make sure the reader can tell who's talking by HOW they're talking.
2. If you're writing is good, the reader should be absorbed enough in your story to KNOW who's talking. There's no need to keep referring to characters by proper name. Keep it to a minimum.
3. Dialogue should be well-paced. It should fit the vibe and feel of the story. By constantly using your characters' names in dialogue, you slow the rhythm, stilt the feel of it.
Here's an example of how NOT to do it:
"George, did you get orange juice when you went to the grocery store?"
"No, Linda. It wasn't on the list."
"How am I supposed to manage running the house, George, without some help from you every now and then? You should've known I meant to put it on the list."
"So, Linda, you think I'm a mind-reader?"
"George, go back to the store and get some. Now, George."
Compare the above to this:
"Where's the orange juice?" The plastic bag rattled as Linda wadded it into a ball and shoved it in the trash. "How did you forget the most important item on the list?"
George shook his head. "It wasn't on the list." He took the list from the back pocket of his worn jeans and ran his finger along each line. "I don't see it."
She turned, snatched the list from his hand. "I know I put it on the list." Her eyes ran down each line once, then twice. "You're right, honey. It's not on here."
"I'll be right back," he said. He kissed her on top of the head and grabbed his keys from the bowl on the table.
Don't you get a better feel for the situation and the characters? Dialogue should be used to move a story forward or to develo character. Don't use it as placeholder or because you're too lazy to impart information in a craftier way. The reader wants to *hear* your characters. Make them jump off the page. (The above dialogue doesn't give one much to work with---it's OJ after all---but hopefully you get the idea.)