More unsolicited sleep advice

Living in Seattle, I have had the bounty of attending Ann Kepler's drop-in moms' groups--part support group, part class on baby care and development. As anyone with young children might expect, the most popular topic is sleep. Where to sleep, when to sleep, how to sleep, how to stay asleep, Dear God I Need Some Sleep, and so on. Personally, I have a baby (OK, fine, not really a baby anymore--a toddler!) who is sometimes a solid sleeper and sometimes quite the opposite. (Note that I did not use the term "good" in conjunction with "sleeper." Ann likes to point out that people place a lot of morality around sleep--that if your baby doesn't sleep well it is Probably Your Fault--and so prefers not to put it in that light. Sleep is often a factor of temperament, which is not something you as a parent have any control over. This also comes in to play if you choose to sleep train [see below].)