How to handle a "nagger-spouse"?

To keep the peace, I'd just let him/her rant and nag. It's what my dad has been doing for years and I find it very effective too haha. Usually, nagging happens when someone is frustrated and "sweating the small stuff". I do make the effort to listen to the important points but when my partner starts repeating his points and turn naggy, I would practice, "in one ear and out the other". Sometimes, they just need to rant and vent their emotions via nagging. I am guilty of that as well and I know my partner does the same "in one ear and out the other" process. I wouldn't argue or belittle his or her topic of nagging -- hell might break loose. Just listen, respond appropriately if needed and move on.