The sh404sef and JoomSEF plugins support multiple categories now. See an example here .
This demo runs the free version of JoomSEF. Download it here .

Educational

Colleges (5)

Universities (5)

Digifeed

Digifeed

Great products - great company!

Lorem ipsum dolor sit amet, consetetur sadipscing elitr.
Flipbox

Flipbox

We have the best products!

Lorem ipsum dolor sit amet, consetetur sadipscing elitr.
Jaxfire

Jaxfire

We do everything!

Lorem ipsum dolor sit amet, consetetur sadipscing elitr.
MIT

MIT

Institute of Technology

Lorem ipsum dolor sit amet, consetetur sadipscing elitr.
Skanyx

Skanyx

Our company slogan!

Lorem ipsum dolor sit amet, consetetur sadipscing elitr.
United Nations

United Nations

It's your world

Lorem ipsum dolor sit amet, consetetur sadipscing elitr.