Broken Sword 2When you are in Quaramonte City, let George offer the goat standing beside the picture by the mining offices the piece of coal: you'll get a great James Stewart-impersonating goat.
(I've heard that you can also fire it from your catapult and something interesting happens, but I can't say what - if anyone has tried this, please let me know!)
In the London Underground, Nico should buy a bar of ancient chocolate from the vending machine in the abandoned Underground Station with the old coin, and then offer the chocolate to the ghost which appears. The, she should go to the end of the tunnel, and turn left - she will become part of a short animation involving Robert Foster, hero of Beneath A Steel Sky.
This is harder to describe than it is to find............near the end, when you are inside the pyramid, you come to a puzzle involving tiles and dials. Rather than spending ages on it, try this: just above the tiles there is a serpentine carving with, to the right, a skull. Have a search around with the cursor (this is old-school pixel-hunting!) - if you are successful, the cursor will become a cross. Click, and the solving the puzzle won't be necessary (not only will the door open, but the skull will have a peek at Nico's decolletage).
Broken Sword 3You only get one shot at this easter egg! After leaving Vernon's apartment for the first time, you should see a skateboarder. Approach him and try to use the lipstick on him. Nico will say "There was no way I was going to do that!" or something similar. Walk down the street until you pass the park: either cross the road, or turn right. If you tried to use the lipstick on the skateboarder, you should the River Seine or the Eiffel Tower. (I can't remeber which exit takes you where). As far as I can tell, this is the only use for the lipstick in the whole game.
I cannot find any Easter Eggs in Broken Sword 4 (I have tried, oh how I have tried
): if anyoone has found some, please post!