In one of your June issues you ran a letter from Frances Segerblom warning of Paris pickpockets who hold up a sign or newspaper to distract you while others pick your pockets or grab your purse. As we were soon leaving for Europe, I clipped the letter and took it along to remind me. Thank you, Frances, and thank you, L.A. Times; the Gypsies are busy in Rome also, with the same routine. Of the 12 people in our party, we had four approaches. Here's an additonal tip to help you keep your wallet: Put a wide rubber band around it before putting it into your pocket. If someone tries to remove it, the rubber clings to the cloth and will tug, giving you a clue that the wallet is moving.