Getting Primary Key Value After Insert

["Adam" <adam@xxxxxxxxxxxxxxxxxx>]

I'm inserting data into two tables, the second table has a forigen key that 
points to the primary key of the first table.

After I insert a row into the first table, I need to take the primary key 
value created in "SERIAL" column and store it so I can insert it as the 
forigen key value on the second table.

What is the best way to get the value of the primary key ( SERIAL data 
type ) of the row I inserted?