Tables

select 'grant all on '||schemaname||'.'||tablename||' to SOMEUSERNAME;'
from pg_tables
where schemaname in ('SOMESCHEMA1', 'SOMESCHEMA2')
order by schemaname, tablename;

Views

SELECT 'grant all on '||n.nspname||'.'||c.relname||' to SOMEUSERNAME;'
FROM pg_catalog.pg_class c
LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE n.nspname in ('SOMESCHEMA1', 'SOMESCHEMA2')
and c.relkind = 'v'
ORDER BY n.nspname, c.relname;

Functions

select 'grant all on function
'||n.nspname||'.'||p.proname||'('||oidvectortypes(p.proargtypes)||') to
SOMEUSERNAME;'
from pg_proc p, pg_namespace n
where n.oid = p.pronamespace
and n.nspname in ('SOMESCHEMA1', 'SOMESCHEMA2')
order by n.nspname, p.proname;

Sequences

select 'grant all on '||n.nspname||'.'||c.relname||' to MYUSERNAME;'
from pg_class c, pg_namespace n
where n.oid = c.relnamespace
and c.relkind IN ('S')
and n.nspname in ('SOMESCHEMA1', 'SOMESCHEMA2');

If you do not have stats_command_string set to on in your postgresql.conf, you will see output similar to the following:

postgres=#  select * from pg_stat_activity;
 datid | datname  | procpid | usesysid |    usename    |        current_query         | query_start |         backend_start         | client_addr | client_port
-------+----------+---------+----------+---------------+------------------------------+-------------+-------------------------------+-------------+-------------
 10793 | postgres |    2275 |       10 | postgres      | <command string not enabled> |             | 2009-02-15 07:50:40.940629-08 |             |          -1
 16712 | isx      |   11447 |    16956 | rails_app0174 | <command string not enabled> |             | 2009-01-07 11:52:52.683856-08 | 172.16.1.4  |       44881
 16712 | isx      |    6037 |    16956 | rails_app0174 | <command string not enabled> |             | 2008-12-30 17:15:17.110313-08 | 172.16.1.4  |       37302
(3 rows)