Identifying PowerPC applications that will not work on OS X releases beyond Snow Leopard?
Solution 1:
I don't have a Snow Leopard install handy but this info is available in System Profiler...
Apple Menu > About > More Info
In the resulting app there should be a way to view the installed applications. In that list there will be a column "Kind" that will state "Intel", "Universal" or "PPC".
Screen shot of how this looks in Mountain Lion: (may look different in Snow Leopard, but idea is the same.)