foo.pl

use strict;
use warnings;
use lib qw/lib/;
use URI;
use XML::Feed;
use XML::Feed::Deduper;

binmode STDOUT, ":encoding(cp932)" if $^O eq "MSWin32";
my $deduper = XML::Feed::Deduper->new(
    path => '/tmp/feed.dat'
);

while (1) {
    my $feed = XML::Feed->parse( URI->new('http://twitter.com/statuses/user_timeline/5209741.rss') );
    for my $entry ($deduper->dedup($feed->entries)) {
        print "new entry:",$entry->title,"\n";
    }
	sleep 1;
}