Well it's not actually a precept. But it is part of 'Right speech' of the Noble Eightfold Path.
To be frank it's pretty hard for lay people to abstain from idle chatter, speaking from my own experience, your peers and loved ones might think you're being despondent or even that you feel yourself superior to them. It's not a good way to act around others in a lay environment.
But as far as abstaining from gossip goes, that is quite possible and beneficial.
If you want to learn more about Right Speech, this page here has a lot of good words of the Buddha on this subject:http://www.accesstoinsight.org/ptf/dham ... amma-vaca/
Speak only the speech
that neither torments self
nor does harm to others.
That speech is truly well spoken.
Speak only endearing speech,
speech that is welcomed.
Speech when it brings no evil
- Snp 3.03
"But, Udāyi, let be the past, let be the future, I shall set you forth the Teaching: When there is this this is, with arising of this this arises; when there is not this this is not, with cessation of this this ceases." - Majjhima ii,32
Nanavira Thera's teachings - An existential approach to the Dhamma:http://bit.ly/LDsGHg