Can you use a Intel app on PowerPC Mac?
Yes and no. You can run Windows software on a PowerPC Mac using
software such as VirtualPC for Mac or Q. A powerful Mac is required
to do this as emulating a completely different CPU with a
completely different architecture is VERY CPU taxing. However,
running an Intel app on a PowerPC Mac is impossible. The code
inside of the program is written for the Intel chipset and not
PowerPC. If you find a "Universal" porgam, that means that there
are two sets of code in that program, PPC and Intel.