###Ruby, 46 characters###
puts" "*8+?*;9.times{|i|puts"%8s0"%(v=?0*i)+v}
In order to change the height you would have to change both 8s and of course also the 9.
The output of the program is as follows:
*
0
000
00000
0000000
000000000
00000000000
0000000000000
000000000000000
00000000000000000
*Edit*: Inexcusably I omitted the output in the first submission.