You may get extra lumber by having your pleasants/peons first chop on some tree(but not cut it down) and then build a town hall or a lumber mill. We will get 50 extra lumber.
You may get any buildings or units(allies or enemies) into your transport if you do this bug. Put 6 skeletons in a transport, and wait for them to decay to nothing, then the next 6 units/buildings made will go into your transport.
I find this bug pretty useful in a water level. Even if you can't see a sub, you can click in a area where an enemy sub is, and the picture of the sub will show up. This is useful when subs are picking on your jugs, and you don't have air support near-by.
More minor and well known bugs are here.....
You can see lumber missing through the fog of war.
When you click on a guy, and then right click the unit to an area repeatedly, the unit will keep say the "okay" speech.