Enter Photojojo, the company known for making smartphone and photography accessories. Their new iPad Telephoto Lens adds an optical zoom to your iPad or iPad Mini. The kit adds a snap-on back cover to your iPad. The lens is removable, unscrewing from the mount area when you don't need it.
In exchange for that bit of inconvenience, the lens adds a 10X optical zoom to the iPad 3/4 and 12X to the Mini. That's a pretty respectable bump, especially considering that the current optical zoom is 0X.
As always, Photojojo offers a bit of self-deprecating wit in pointing out its products' slight deficiencies: "The iPad telephoto lens has a manual focusing ring to give you added control over its delightfully shallow depth of field. It also adds just a bit of vignetting and a dreamy lo-fi look."
In other words, this ain't no fancy Nikon lens. But it will bring you much closer to the action, vignetting and "dreaminess" notwithstanding, with far better resolution and focus than you could ever achieve with digital zoom.