sli on intel board

[shovenose]

mobo: intel d955xbx atx running a p4 3ghz.
can i sli on it, xfx geforce 6600gt 129mb ddr3 dual dvi pci-e...
the mobo has 2 pci-e slots but can it do sli?????????????????????????????????????????

 

[shovenose]

oh and do i need one of those flat wire thingies that go between the cards?