PLSQL Question regarding multiple inserts

Hi all. Quick and perhaps silly question, but...

I am using Pg 7.3. I am writing a function using pgplsql. This function will
perform multiple inserts. Let's say two of the inserts are as follows:

-- id is primary key
insert into users (id, username) values (nextval('someSeq'),'somename');

-- id is also a PK
insert into log (id, uid, message) values (nextval('someOtherSeq'),XXX,'New
Account');

Assume XXX is the id from the first insert. How do I get that number? Not
currval('someSeq') -  'cause someone else may have performed an insert - but
the id for that specific insert.

Thanks,

HG