Give photo pad a try. It is produced by Zagg and I am stunned at the quality of this app.
Yeah, I downloaded this last week, its a great app.
Do a search in the app store for photoshop.com .... It is an iPhone app but to me at least is more powerful than photopad. And yes, it is the real deal, from Adobe.
I do await the day when then truly professional iPad apps start showing up.....
iPad 1st Gen 16G
^^ I agree, the adobe app is awesome.
I personally like Filterstorm. Go check out the cool video tutorial at filterstorm.com