Haha, yep, I had exactly the same thought and was looking for another transverse set-up that might use a true center diff. I haven't found one yet
Evo - I could only find info on a couple of models, but they seem to be similar to haldex but with the hydraulic pressure fully computer controlled
Celica GT4 - Viscous coupling
Volvo 850 - Viscous coupling
Newer Volvos - Haldex
There's some I've not checked yet though, Pulsar GTiR, Mazda 626 etc..