With the Gimp calendar plugin it is easy as 123 to create calendars from your photos.The plugin for GIMPis based on the calendar plugin by Moritz Mekelburger and has been improved with some additional functionality.The most important being the possibility to create 12 calendar sheets, one for each month, at once. Also the dgree of transparency for the calendar backround can be chosen freely now.
The Gimp calendar plugin can be downloaded free of charge and was published under the GPL.