Adobe Photoshop Express
Adobe’s first crack at mobile image editing is the free Photoshop Express, offering many of the same capabilities as iPhoto: Crop, rotate, straighten, color, filters, effects, and even borders, which iPhoto currently lacks. It’s hard to argue with free and the app taps into Photoshop.com cloud storage, but it’s nowhere near as refined as iPhoto.

Camera Awesome
It may not be iPad native, but SmugMug’s free Camera Awesome pretty much lives up to its name. While its primary task is for shooting pictures, the app offers a wide range of standard features plus an “Awesomize” mode, which aims to improve anything you can throw at it. Of course, SmugMug photo sharing is tied right in, along with YouTube (for videos), Picasa, and Photobucket, which iPhoto lacks.

Halftone
Although its primary purpose is to turn your images into slick comic-style panels, the 99-cent Halftone offers a wide range of image editing features, including crop, rotation, brightness, contrast, saturation, and more. The price is right, it’s universal, and just got updated for the Retina Display of the new iPad -- so what’s not to like? You can even share your creations as real, physical postcards through the mail, as well.

Photo Editor+
You could buy iPhoto, or you could buy the 99-cent Photo Editor+ and four other apps with the same price. Offering largely the same feature set as Apple’s wunderkind, this app beefs up the filter and effects options while allowing you to actually draw or paint on images, and even clean up blemishes with ease. The fact that it’s universal certainly makes us love it all the more.

PhotoForge2
While the original PhotoForge is still available, the sequel is where it’s at, featuring full resolution editing, layers and a slick UI with all the trimmings. PhotoForge2 also lets users edit IPTC and GPS metadata and one-ups iPhoto when it comes to sharing, adding Dropbox, Picasa, Tumblr, and FTP into the mix. All this for only $2.99, and it’s a universal app!

Photogene
Available as a 99-cent version for the iPhone as well as a $2.99 iPad edition, Photogene was one of the earliest entries into the App Store image editing category. Both apps offer a wide variety of features (including some that iPhoto missed, such as denoising) and plenty of extra sharing options like Dropbox, Picasa, and FTP. Additional pro features can be added via in-app purchase.

Adobe Photoshop Touch
It may be twice the price of iPhoto at $9.99, but Adobe’s recent Photoshop Touch is (mostly) the real deal for image editors and artists, allowing users to paint and retouch with desktop-class layers, effects and more. The only downside (aside from the price) is that creations are limited to 1600x1600 pixels for now, which is far less than that swanky new iPad is capable of displaying.