How can I databind to a ToolStripItem?

Unfortunately, the ToolStripItem class itself does not implement databinding features. However, it is not so hard to add in these features through the magic that is the IBindableComponent interface. You can now make any component you like implement databinding through the use of this interface. 

Here's a quick sample on how to implement it:

public class BindableToolStripLabel : ToolStripLabel, IBindableComponent {
#region IBindableComponent Members

private BindingContext bindingContext;
private ControlBindingsCollection dataBindings;

public BindingContext BindingContext {
get {
if (bindingContext == null) {
bindingContext = new BindingContext();
}
return bindingContext;
}
set {
bindingContext = value;
}
}

public ControlBindingsCollection DataBindings {
get {
if (dataBindings == null) {
dataBindings = new ControlBindingsCollection(this);
}
return dataBindings;
}
}

#endregion
}

Now there's a giant caveat here: If you want to hook up to the same currency manager as something else in your form, you may want to try to fish the binding context out of the owner ToolStrip or the form instead of creating a new one.

I'd go into more details, but I just can't do it as much justice as this great FAQ on databinding.