I am making a Java Application and one of the features I want to add is tracking users and reporting their check in time to the application (to be seen by management). This is a B2B solution that I intend to market to a variety of customers. I am trying to figure out
For testing and developing I'd have a look at one of the Arduino varietes around. I don't have firsthand experience with Arduino and RFID myself, but the platform itself is very easy to get into, especially if you know some C/C++.
Just google Arduino and RFID and you'll get lots of hits.
Cheers,