You can override the drawRect for the search bar. By Setting the "UISearchBarBackground" view to an alpha of 0, it will paint it the flat tint color you set. For example, in your App Delegate add this:
@implementation UISearchBar( CustomBackground )
- (void)drawRect:(CGRect)rect
{
// Find the UISearchBarBackground view and set it's alpha to 0 so we get a "flat"
// search bar.
for( UIView *subview in self.subviews )
{
if( [subview isKindOfClass:NSClassFromString( @"UISearchBarBackground" )] )
{
[subview setAlpha:0.0F];
break;
}
}
}
@end