DS is 16 weeks and a fantastic night-time sleeper. We introduced a bedtime ritual pretty early - around the 5 week mark - and shortly afterwards he started sleeping from 'bedtime' (eg 8pm) through till morning with just one or two night time feeds. From 12 weeks he started sleeping the whole way through, although he still wakes for a feed at around 4am on a lot of nights.
Basically though we rock or breastfeed him to sleep (well, DH or I rock/sing to him and/or I BF him!), and my mum was a bit horrified we don't put him down in his cot and allow him to get himself to sleep. My friend whose baby is 5months puts hers down in this way too. I'm just not sure when we should have started doing this! My DH is convinced we need to start leaving him to settle when he's sleepy rather than putting him in his cot asleep, but the problem is that BFing makes him so sleepy that he's usually asleep when I put him in his cot anyway, IYSWIM.
Any tips or info on when your DC were able to do this would be great!