Todd -
I've done these with the picture mats the last 2 cruises.
Basically I have taken a Photo Mat to guest services, usually just before the life drill. The item (in my case the mat) has to be in a bag or envelope when you give it to them. With the item they ask that you supply the sharpies you wish they use (I throw in assorted colors). Your bag or item is then returned to your cabin the night before you depart with your markers, etc.
If you are using a photo mat you want to make sure you take painters tape and tape the edges that go under the frame so that the signatures don't go out of bounds and look weird when you place your mat into the frame.
I have these in my office at home with our favorite photo of the cruise. it's really a unique souvenir that doesn't cost anything. They both have the Fab 5 and Princesses. Not sure who else, if anyone else, has signed them. I will need to look
The pillow case is just what you thought. Folks do put them on pillows and then use them for decor. One of my cruise mates last year picked up a sports jersey in DTD and had that signed. He was then going to have it framed for their game room. I thought that was a neat idea.
Guest Services will tell you one item per cabin as they are usually swamped with these items and they only have a short time to do this on the 4 days.
Oh and I put my photo mat in a padded envelope, in the middle of my suitcase between items to ensure it stays flat and doesn't get cracked. Haven't had a problem yet.
Hope that helps.
