For the bard-chatter project I collected all of Shakespeare's work and split it up by punctuation. All of that data was collected on a local database. Now I'm in the process of pushing that database to MongoLab. Below are the terminal commands for exporting from localhost database to bson and then importing to my MongoLab database from bson.

First the localhost mongo server has to be up and running:

$: mongod

Then we open up another terminal window and start pumping all the database collections to local BSON files:

$: mongodump -h localhost -p 27017 -d bard -o /Users/davidraleigh/code/temp/bard-dump/

Now for pushing all those local BSON files to MongoLab:

$: mongorestore -h <yourMongoLabURI> -d bard-db -u <username> -p <password> /Users/davidraleigh/code/temp/bard-dump/bard/

If I only needed to update one collection, in this case the 'phrases' colleciton, you would go about it using the below commands:

$: mongodump -h localhost -p 27017 -d bard -c phrases -o /Users/davidraleigh/code/temp/bard-dump
$: mongorestore -h <yourMongoLabURI> -d bard-db -c phrases -u <username> -p <password> /Users/davidraleigh/code/temp/bard-dump/bard/phrases.bson