There's a plan to enable NFC in Tallinn public transport. Instead of waving a card at the reader on the bus you wave your phone. Which I'd like, it remains to be seen whether they'll manage to implement it. I don't want another RFID card in my wallet interfering with the other cards.
It be great if I could register my NFC phone for all the places where I have a card instead of a physical key to open doors. Home, home garage, work, work2, etc. I know the frequencies don't match though.
Getting rid of the physical wallet altogether sounds good to me too.
As for security, that's a technical problem. Let's hope it can be done with NFC. A confirmation on the phone for transactions would do it.
And isn't NFC enabled on most smart phones these days, not just the S3, except for iphones? gsmarena found 133 phones with NFC: http://www.gsmarena.com/search.php3 Choose NFC required and hit search.