using the "copy from" command to load tables from a txt flat file

Hi out there,

I'm a first-time user of the "Copy ... From..." command, and I'm trying
to load a table from a text flat file.

http://www.postgresql.org/docs/7.4/static/sql-copy.html

I don't know if I'm using the command correctly.
Question: I run this command as a superuser, and the "copy from"
command is run like a SQL command on the command line, correct?
I get the following error. Any suggestions would be greatly
appreciated.

[mknepper(at)barney datafiles]$ psql -U postgres medispan
Welcome to psql 7.3.4, the PostgreSQL interactive terminal.

Type: \copyright for distribution terms
\h for help with SQL commands
\? for help on internal slash commands
\g or terminate with semicolon to execute query
\q to quit

medispan=# COPY mmw_ade_com FROM
'/home/mknepper/medispan/datafiles/mmwadecom.txt' WITH DELIMITER '|';
ERROR: COPY command, running in backend with effective uid 500, could
not open file '/home/mknepper/medispan/datafiles/mmwadecom.txt' for
reading. Errno = Permission denied (13).
medispan=#

Table schema:

CREATE TABLE mmw_ade_com
(
gpi VARCHAR(14) NOT NULL,
mcid INTEGER NOT NULL,
restrictionid INTEGER NOT NULL,
sequencenumber SMALLINT NOT NULL,
textid INTEGER,
PRIMARY KEY (gpi, mcid, restrictionid, sequencenumber)
);

example of data, from the TXT flat file, called mmwadecom.txt:

01100040100310|5|0|10|14608
01100040100310|8|0|10|17377
01100040100310|8|0|20|18061
01100040100310|8|0|30|14608
01100040100310|22|0|10|18025
01100040100310|30|0|10|14608
01100040100310|36|0|10|14608
01100040100310|115|0|10|13937
01100040100310|115|0|20|18041