iPhoto has several Special Effects ready to play with, accessed with a tap on the little sparkly icon, the fifth from the left in the lower left corner of iPhoto on the iPad. Tap that, and a fan of special effects swatches will rise up from the bottom of the screen. There are six filters there, including Warm & cool, Duotone, Black & White, Aura, Vintage. and Artistic. Tap on a swatch you’d like to apply, and then tap or drag along the strip to select the effect that you prefer. Many of the filters can be further tweaked by pinching or dragging around in the photo itself. For example, the Vignette effect, found at the right within the Black & White strip, can be enlarged with a pinching out gesture, and moved around to a new center point with a simple drag. Play around and have fun here. Tap the question mark icon at the top for a tooltip for each of the effect swatches.