For those who would like a somewhat gradient status bar without having to jailbreak their phone. I used screenshots of the Settings window to create this wallpaper. The gradient effect comes from Apple's use of a semi-transparent status bar. This allows the user to add a gradient in the wallpaper that sits behind the status bar but shows through thanks to a semi-transparent status bar. I've also added a nice indentation for the paginator dots. Feel free to use this as a wallpaper or as a template for your own wallpaper creations.
I've uploaded the wallpaper to the forum wallpaper section and it can be found here:
Status bar wallpaper
Anyone desiring to add a grdient status bar to their wallpaper should add a gradient starting from the top of an image spanning 40 pixels down. The wallpaper should be 640 x 960 for best results.
UPDATE (May 5, 2012): I've uploaded some templates for the home screen and lock screen backgrounds. Templates are in .psd (Photoshop) and .xcf (GIMP) formats and can be found in this thread.