It is easy to get a Kenyan Visa on line to avoid waiting to fill one out at the airport.

Go to

Click on the "Consular Information" tab and drop down to click on "Visa Information"

 Scroll down to last printed page and you will see the VISA form

Print it out (one for each person)

 Fill out the VISA form, and you are ready to go.

 Put it with your valid passport, along with $50 (newer bill with the larger picture) and present the package to the officer after you depart your plane.  This will be before you have access to and pick up your luggage.  No photos are required.  (Read the info above the application on the site to be sure this applies to you, and there have been no updates or changes.)