One of my favorite projects on my wall is what I like to call my "Gallery of Sons." In person it looks like canvas, but really, I've used scraps from the ends of 1x12s!
The cheap pine 1x12s I use are only 11.25" wide, so I cut my scraps into 11.25" x 11.25" squares and then painted the edges black. I was able to get 12" x 12" matte prints on regular paper for $1.50 a piece (more on that below) and the traced the wood pieces on the prints to cut it down. Instead of mod podging or gluing the prints on, I used double sided tape, so I could switch the pictures out, which I have successful done two times already!
I put two of those saw tooth picture hangers on the back.
A lot of people ask me where I get my prints done. I've heard you can get square prints done at Costco, but I got mine done on regular paper with a matte finish from Scrapbooks to Share for only $1.50 a piece (there's a flat rate for shipping, so you'll want to order several at a time). I'm not going to lie, the website can be pretty tedious and confusing. (I linked it to the place where you upload pictures to save you the scavenger hunt of finding it on your own). I suggest cropping and saving your photos into a square in Windows Media or something similar before uploading it to the website. Then, after you upload and select an image, under "Print Sizes" you can click the drop down feature to change it to "Regular Borderless" instead of "Cardstock Borderless." Once you go through checkout you can edit options to select matte finish instead of glossy.
I'm not being paid to endorse Scrapbooks to Share, I have just been pleased with their prints even if ordering them is tricky.