This is an updated version of Arda Kutlu's script "Mass randomizer",
it can now handle groups, you can also select a random amount of sub-object elements.
update 2.0.2 : as requested by dmitry belonosov, you can now shuffle objects position, there is a new button in the position tab.
I didn't add group support for this function, i'll do it in next update...
update 2.0.3 : now you can shuffle groups positions, i also changed the way rotation, position and scale works with groups when "Group As One Object" checkbox is unchecked, it will now ignore the grouphead so that the objects within the groups are threated as if they where not part of any groups.