My DS has just given up his sleep at 24 months. He had one today but it's like a once a week thing. I battled with it for around 4 months before conceding it is time to drop it. He is very happy without it and will go to bed 6/7pm instead of 9/10pm which he does if he has a nap.
I do insist on going through the nap routine everyday and either lying with him or leaving him to chat to himself for at least half an hour though as I really think that down-time is important.
My best friend's DD (same age) does go through phases where she won't nap for 2 weeks at a time then goes back to it but she is asleep at 8pm regardless of whether she naps or not.
As lovely as a rest break during the day is, I love love love a 7pm bedtime much more.