If you use FxCop, you'll get lots of globalisation warnings.

On full rules it will want you to make your lieratls resources or constants as well.
Another thing you might want to look at, is passing format specifiers to ToString instead, If you do a lot of it.
String.Concat("Total : ", SomeNumber.ToString(CultureInfo.CurrentUICulture));
for instance
And for really long complicated ones, use the StringBuilder class.