S2scott - Hey
I too was confused by the term "sip card" -- I did a little researching my self and came up with nothing. The only thing I could think of is what most third party SIP devices currently do; Route - We sell a product called a Sip-A-rator, ours are from bandwidth.com -- Essentially its a router that accepts many formats of SIP. As we all know there's no official standard yet.