The Los Angeles Conservancy (213/623–2489 www.laconservancy.org) regularly conducts Saturday-morning walking tours of Downtown architectural landmarks and districts.
Tours begin at 10 am, last about 2½ hours, and are offered rain or shine. Call for schedule and fees.
Starline Tours (323/463–3333 www.starlinetours.com/los-angeles-tours.asp) offers a wide range of sightseeing tours around town. It’s an ideal way to get a taste of Los Angeles without the hassle of figuring out transportation.