I know that there are some online places where you can have an odd sized photo developed... but cannot for the life of me remember where...Also I thought I remembered Creating Keepsakes having an article with an online photo guide to having pictures developed and I cannot find that either... Can someone please help?? Thanks!!
Okay not exactly what you asked for, but I've been able to print pictures in 3X3 size by making collages of several pictures and printing them as 4X6 or 5X7 or bigger. So for example, I can fit 2 3X3 pictures onto a 4x6 print. I use Picassa to crop my photos into squares. Then I open up the collage maker and drag the 2 square photos onto the 4X6 format, put them side by side, adjust as necessary to fill up the 6" length and voila, you have 2 3X3 photos. Yes there will be extra space left on your 4x6, but that can be remedied by cutting the end product. Hope that makes sense.
It's a little time consuming but works great because now I can have photos of any size. I can just upload those 4X6 or 5X7 to Costco or somewhere similar.
The program that came with my HP photosmart printer allows me to print pictures of almost any size. The only thing that kind of stinks is it wastes photo paper because you still print the pictures on 4x7 or 5x6 paper. It is convenient, though!
scrapbookpictures.com prints a lot of different sizes! i don't remember which sizes exactly, but i ordered from there a couple months ago and the quality was amazing! i was really impressed, they only thing i didn't like was waiting so long for them to come in the mail!
I have a MacBook and primarily use iPhoto for odd-shaped pictures. If that doesn't give me the size I want, then i'll use Gimp (which is like PhotoShop but free and available for Windows and Mac). I will then crop it and change the canvas size which changes the print size. I can go in and manually change the units of measurement to inches and print whatever size picture my LO calls for. I have recently begun to play with it and like it. I hope that helps!
Before I got my Mac I used ArcSoft photo printer. It let me print an 8.5x11 sheet of pics in whatever size and shape I needed. Which was awesome but it is not Mac-friendly. I had this a few years ago when it cost for the CDROM but I don't know if it still costs to download it or not since it IS an older software. ArcSoft also has an easy to use scan and stitch software too that I used when I had Windows.