Originally Posted by virus007
(Here at the university we use a NFC card to check in. Is it possible to copy the tag to my phone so I don't have to carry my student card around?)
I believe this is not possible right now, as there are security measures in place to prevent fraudulent use, but give it a couple of months there will be apps you can download , to copy re-writeable NFC tags to your phone, making your phone work as an emulator of some sort.
To emulate cards with your NFC phone, you have to have full control of the secure element. In the Nexus phones, access to the secure element is restricted to Google - only they have the codes to access it. In non-Nexus phones like the SGS2, they don't even have built-in secure elements and therefore have to rely on SIMs, which are in turn controlled by operators. Without access to the secure element, you won't be able to emulate another card. So, no, even in a few months you won't be able to copy a tag and emulate it from your phone. Unless Google opens up the secure element to, which is unlikely.
To OP: Even if you could actually copy the contents of the card and then emulate it, this might not be enough. Many schools use just the UID of the card to associate it with your account on their system. This means that there's a good chance that your card actually has no data on it. Furthermore, phones aren't currently able to emulate UIDs. You're out of luck.