I love photbombing .. especially when it is done well. I think this is the best photobomb I have ever seen. What makes it so great is that it is a perspective photobomb.
Source: The Daily What
Here are some other photobombs I really enjoy.
When you got to Pisa, you have to do the "holding up the tower perspective shot." The whole place appears to be packed with frozen mimes. Anyway here is my Pisa Tower Shot - at the time they were trying to make sure that the Tower leaned but did not fall over. This is truly the world's most famous mistake.