UILabel Strikethrough

You could create another UILabel above your label and use an en dash character:

label.text = @"––––––––––––––––––";

Caveat: works with Helvetica (system default). It may not work with other fonts.

iPhone doesn't support attributed strings (which is usually the way you'd do this in Cocoa), so I don't believe it's possible.

You could subclass UILabel and draw the strikethrough yourself. I've also seen some people use a UIWebView to do this type of thing, but that seems like overkill to me.

This is an old question and newer information is available.

Starting in iOS 6, we have NSAttributedString.

For pre iOS 6, I would look at TTTAttributedLabel

UIView* slabel = [[UIView alloc] initWithFrame:CGRectMake(label.frame.origin.x, label.frame.origin.y+10, label.frame.size.width, 2)];
[self addSubview:slabel];
[slabel setBackgroundColor:label.textColor];

You can add a view over UILabel and style it with label properties.