I've just finished my first cut at a native Solitaire game. You can download it from my website http://iphone.rustyredwagon.com.
The specific version of Solitaire is Klondike (the same one you play under XP named Solitaire). I have not implemented scoring, time etc etc but I wanted to get this version out there as it's playable as is.
There is a basic properties screen available by double tapping the table where you can start a new game and change the draw number (1 or 3).
I'll try and get this available via installer.app as soon as I can but for now it's available via my website as a zip package.