Sequences, defaults and getting a new key

[Jeff Willden <jeff(at)pavanell(dot)com>]

When the primary key of a table defaults to the nextval() of a  
sequence, if you insert a new record into the table and accept the  
default, how do you then select the value that was just used as the  
new primary key and guarantee that you don't accidentally get the  
value that another user just generated at about the same instant?

Thanks,

Jeff Willden