How I Met Your Mother?s popularity has been, quite appropriately, infectious like some sort of venereal disease. Taking the template of Friends and leaving the casting of the ?Rachel? character an ongoing mystery has managed to ensnare the attention of young whatnots across the land.

Season 5 shows no sign of slowing things down, indulging in this hump stage ? like most US sitcoms do ?by throwing some extra cameos into the mix, flapping their proverbial arms for attention like an annoying child.

Jennifer Lopez, Rachel Bilson and Chris Kattan all duke it out for the converted title of ?Most Outdated Celebrity?.