As Tom Toles tells us today, he has decided to retire. After a half-century of brilliant cartooning, including 18 years at The Post, he is entitled, but we will miss him greatly, as we know will many of you. While we search for a replacement, we will offer a cartoon every day chosen from a roster of the best cartoonists in the country. You also may continue to enjoy the work of our other staff cartoonist, Ann Telnaes. — Fred Hiatt, editorial page editor