MANY American and British children were raised to write thank-you notes to people who sent them gifts or invited them to parties. Now that the holiday season has arrived, parents will once again break out stationary and nag their kids until they scrawl out a few hand-written “thank-yous”. However, a recent commentary on the Guardian's website asked readers whether thank-you letters are still important in an age of e-mail and texts. Here's how some answered: