Owners of non-SLI enabled motherboards (with two PCIe slots) who wish they'd gotten an SLIable board in the first place are going to be mighty pleased at this one. Not so long ago there was a patch released from ULi/NVIDIA which was designed to allow motherboards specifically using ULi 1695/7 chipsets to make use of full SLI functionalities. However, it wouldn't work with other dual-PCIe motherboards out there.
Since then, a little birdie has ripped open the patch and played with its gizzards. Result? A modified patch which works on *all* chipsets, providing the board has two PEG adaptors of course.
A while back Asrock published a SLI enabling patch for their ULi chipset based motherboards that have two PCI-Express slots. Various rumors suggested that the patch would also function under other chipsets as well, and allow users with other chipsets to use SLI on their non-SLI motherboards. Unfortunately the original version of the patch installs only on ULi 1695/7 chipsets - you couldn't use it if you didn't have a motherboard with that particular chipset.