There's another one but I can't remember the details properly... perhaps someone else knows about it. When you walk past Eva for the first time with the balloon animals (when she says "What's that horrible squeaking noise you're making?", there's something that you can do to make the line come out of the other character's mouth, but I can't remember what.
I would check but its late Can anyone verify this?
I would but I lost GF disc 1
I found this one on the GFC, but I think it's slightly different:
Go to Eva's desk next to the hole punch. After punching the playing card stand aside and wave the card at Eva (hit enter). She will say "Maybe card tricks some other time when I'm not so busy."
Now turn about a quarter turn without moving left or right. Hit enter. Manny will say "I don't feel like pitching cards right now."
Here's the Easter egg. While Manny is saying "I don't feel like pitching cards right now" Turn and face Eva. Before he is through talking hit Enter again.
Eva will say her line, but it will come out of Manny's mouth!!! Try it!