I have a question on EJB design. I'm about to create an EJB system for an online store, which sells various kinds of products. To begin with, the store will sell tangible products only (like books or CDs). I want my design to be as flexible as possible, though, so that other kinds of products (also intangible, like travels) can be easily added at a later point.
I'm fairly new to EJB, so I'd be very interested in hearing your thoughts on this. If you were in my shoes, how would you go about creating a good, flexible EJB design for various kinds of products?