While setting up the Ohio Divide Consulting page at Facebook, I needed to set a profile and cover photo.
Following Brian‘s advice to establish a consistent identity across the Internet, I chose the Ohio Divide Logo as the profile photo.
For the cover photo, I decided to duplicate the header from the Ohio Divide Web site.
Using the template from Facebook
I created this image
The resulting combination looked like this
which was all well and good until I viewed the site on my smart phone and it looked like this
A quick calculation shows that the cover image used on phones is created by scaling up the standard cover photo by eight sevenths then center cropping to 640 pixels wide.
Reversing the calculations shows that from an 851 x 315 pixel cover photo, the middle 560 pixels are used, as shown here
Using this information, I created a template which combines both the standard and mobile rendering of the cover and profile photos