Unless you plan on dumping her, you are going to have to learn to anticipate, deal with, or simply avoid her nagging. Here are some ways in which you can do just that:
1- If you're coming home late and didn't call, be ready for it when you walk through the door. Bring her flowers and tell her that you had to drive around for hours trying to find a place that's still open.
2- Most women give off signals when they're unhappy. If she gets unusually silent, ignores you, or just seems generally different, it's about to hit the fan.
3- Listen to her. Whether you want to believe it or not, most women will generally tell us at least once or twice what it is that they are ticked about; we just don't hear them because they speak in a special code that only other women can understand. But if you listen really closely, you might get enough out of what she's saying to try to save yourself some of the hassle.
Deal with it
1- The zone-out method. We all do this subconsciously, you just have to learn to develop the talent to a point where she won't notice you're doing it. This is where you simply nod, smile and agree with her while not hearing a single word she says. In one ear, out the other. Just learn to be responsive to the phrase "Are you listening to me?" But if she says, "What did I just say?" you're on your own buddy.
2- The "You're right" method. This one gives you the element of surprise. As soon as she starts in, you beat her to the punch. "I know sweetheart, I should have mowed the lawn last week, sometimes I don't even know why I forget to do these simple things." She will probably be so amazed at the words, that she'll let you off the hook so you can get back to ESPN.
1- Do something unexpected and counteract any nagging that may potentially be on the way, kind of like stocking up on anti-nag fluid.
2- Try to figure out what she's angry about before she tears into you, and fix it. If you're proactive she won't have anything to gripe about and you can move onto more important things like the Packers game.
3- Break it off. If the nagging gets to a point where you just can't take it anymore, then it might be time to let go. There is no use in beating a dead dog; chances are that you both already know it's over, and maybe that is one of the reasons she is griping so much.