This taken off another forum from a poster that uses NFC routinely:
"Many people are aware of NFC as the technology expected to power the future of smartphone payments. What many people don't realize is that NFC has a lot of other practical uses right now. I've been using it for some time now to great effect, mostly for automation purposes.
There are a few things you need to make use of NFC at the moment. For starters, you need an NFC device. I use the Android-powered Samsung Galaxy Nexus and Asus Nexus 7. There are a lot of other Android devices with NFC, as well as several NFC-enabled Blackberrys out there, and Windows Phone 8 will support NFC. However, most of what I talk about here is specific to Android. There may be similar Blackberry apps available, but I've never looked.
You will also need blank NFC tags. You can buy your own tags for a few dollars online. Most tags are re-writable, but be warned; there are different sizes of NFC tags, and if you go too cheap they may not be big enough to store anything of practical value. I'm no expert on the tags, but the ones I bought seem to work well. I bought 10 from eBay. They just look like small white stickers, about the size of a quarter.
The last thing you'll need are some apps to program and respond to the tags. There are a lot of them out there, but two I use the most are "NFC Task Launcher" and "Tasker". NFC task launcher can write the tags, and can issue some rudimentary phone commands. The app's real strength is the ability to set NFC tags to trigger Tasker tasks. If you've never used Tasker, it's an extremely powerful phone automation app. Tasker can respond to all kinds of inputs (eg plugging in headphones, receiving a particular SMS message, reaching a certain time, etc) and can respond however you wish. For example, in one of my tasks, when my phone receives a particular SMS message, it locks the phone under a password, silences it (so you can't tell when you receive messages), enables GPS, and texts back current GPS coordinates. Together, these two apps make a very powerful combination.
Some of my NFC tags are very simple. One in my wallet allows me to quickly add myself as a contact to NFC-enabled Blackberrys and Android phones (if they choose, I can't do it surreptitiously). If I had a business card, I might stick it to the back of that. You can also have them launch URLs automatically.
I have one on the side of my washing machine, so if I swipe my phone past it when I turn the machine on, it sets a timer for 59 minutes (the normal load time on my machine). Another one on my desk at work that turns off my ringer when I put my phone down. I've heard it suggested that you stick one to the inside of the light-switch plate in your front hall. When you leave the house, you can swipe past it and have it enable or disable wifi.
You can get much more complicated. I know some people have their work tags setup to change their wallpaper and ring-tones to something more appropriate for work, just in case. You can also set it so that if it's after 4 pm, it sends a text to your spouse that you're on your way home.
I have a tag in my car so that when I put my phone down where I normally leave it, it turns on bluetooth and connects to the car's handsfree, as well as my OBDII transmitter, turns on GPS, reads any incoming text messages aloud, and (just for fun) reads out the current date, time, and expected weather conditions for the day. If I plugged it into the car charger before I put it down, it also turns on my wireless hotspot (for potential passengers). When I get out of the car and swipe my phone past the tag again, it switches back to normal (disables bluetooth/GPS and stops reading texts aloud)."