Flatten table using timestamp and source

Good day.

I am quite new to Postgres, so please bear with me.

I  have a table with data in the following format:

Table name : Time_Source_Table

Source , Stime

1, "2012-05-24 13:00:00"

1, "2012-05-24 13:01:00"

1, "2012-05-24 13:02:00"

2, "2012-05-24 13:03:00"

2, "2012-05-24 13:04:00"

1, "2012-05-24 13:05:00"

1, "2012-05-24 13:06:00"

I’m trying to get to a result  that flattens the results based on source, to look like this:

Source, Stime, Etime

1, "2012-05-24 13:00:00","2012-05-24 13:02:00"

2, "2012-05-24 13:03:00","2012-05-24 13:04:00"

1, "2012-05-24 13:05:00","2012-05-24 13:06:00"

Where  Etime is the last Stime for the same source.

Any suggestions would be much appreciated.

Regards

El