What if your company/client has rolled out an access card system… You know, the sort that you swipe your card across a reader, it beeps green and doors open… and you’d like the same functionality for your mobile apps? Something like, the user swipes their card, and an app opens, detects the user, and displays the appropriate data according to who the user is. By extension, you can build an app that requires two factor authentication, e.g. a PIN number (something you know), and the access card (something you have). This proof of concept is something I built to show off that android phones and apps can actually support such scenarios through NFC.
Watch a video of it in action here:
http://www.youtube.com/watch?v=LYIEctwCzuc
And you can find the source code here:
https://github.com/dvas0004/droidNFCdemo/blob/master/src/me/davidvassallo/nfc/MainActivity.java
References:
- http://developer.android.com/guide/topics/connectivity/nfc/nfc.html#tag-disc
- http://developer.android.com/reference/android/nfc/Tag.html
- http://developer.android.com/guide/topics/ui/notifiers/toasts.html
David Vassallo's Blog 
Good stuff man, it might be worth mentioning Apache Cordova & the Phonegap NFC plugin. With these free & open source frameworks you can very simply build an NFC app using Javascript / HTML. We use it for the NFC ring app =) Cheers for sharing and good luck on your NFC Travels!
Thank you. I definitely will try carve out some time to look into your suggestions, thank you!