Anyways- we moved Mateo to his new room last June around his birthday and I really hadn't put much on the walls. Since my 2 1/2 year old is obsessed with putting together jigsaw puzzles at the moment, I decided to glue together some of his 24 piece puzzles and hang them up like posters. 
Mateo's little work table that has become his "puzzle table".
I found some modge podge in the basement and glued the puzzles together over some wax paper on a cookie sheet. I did need to crack the window!
The modge podge glue gives it a nice glossy finish and I used used a small paintbrush that I had in my teaching supplies....though a bigger one would have been easier. My bottle of modge podge had a price tag of $5 and I barely made a dent in it. Once the front dried I also did the back. Not for looks but just for stability. "Puzzle glue" is the same thing.
My mom gave me the idea of gluing thin wood on the back so one Saturday morning Aaron and Mateo took a "man field trip" to the hard wood store and found some perforated board that would be suitable. It cost $6 for a large sheet and he only used about a third of the board for four puzzles.
Clifford!
Mickey Mouse!
Cars!
Winnie the Pooh
So now Mateo has 4 "Puzzle Posters" on his wall that he put together himself and have some of his favorite characters. And it cost just a few dollars plus the puzzles themselves.