Usually at Christmas time they have kiosks in the Malls and shopping centers filled with calendars, I would check that out. And if you can't find one local look on amazon they'll have one. If you take 12 snapshots you like to your local kinkos, Staples does it, Print King usually any of the quick print places or traditional Print Shops ~ they will do a calendar for you and they are cheap, but very cool because it's filled with pictures you love. I used to have them made for the Grandparents each year when my boys were growing up and it was the gift they looked most forward to.
Oh my gosh I never thought of doing it myself!!! I have a fantastic iMac that probably does if for me (or almost) and my pic's are in iPhoto (which is the only place I can seem to get to right now---hence no pic on our chat site)
And, if laziness, business or just plain incompetence gets in my way the Staples idea is wonderful!