You can also use the MAX2719.
It can drive up to 8 * 8 = 64 LEDs
without additional components (power transistors)
And can be cascaded very easy on the same 3 lines.
It includes also digital brightness control.

I use it to drive 7 segment displays.

My example code:
http://www.specs.de/~danni/ap...ax7219.htm


Peter