I'd like to replicate in miniature a big Christmas light display my dad did in front of out house when I was a kid.  He's in his 70s now and I think it'd be cool to show him his work had impact.  Anyway, that means I have to build a miniature 1-2' tall replica of the display (a tree with a star on top) using dozens of LEDs.  My dad used an ancient microcontroller computer back in the day (about half the size of a cinder block if memory serves!) to turn the tree, "lights" on the tree, and star on and off in sequence.  I even remember the sequence and I'm all ready to go....with just one problem.

Each output from an Arduino only powers 1-2 LEDs each.  I need to drive dozens, and I need to do it as simply and inexpensively as possible.  The local arduino retailler sold me a SparkFun TLC5940 on his recomendation, but it only seems to drive up to 15 extra outputs; when I got home I checked the specs and it also seems more suitable to things like servo motors?

Where would you go from here if you were me?