Four-arg select returns -1 if it is interrupted, 0 if timed out. Using that and Time::HiRes, here's a demo,

#!/usr/bin/perl    # file: sigdemo
use warnings;
use strict;
use Time::HiRes qw/gettimeofday tv_interval/;

$SIG{INT} = sub {};

my $timer = shift;
my $start = [gettimeofday];
{
    last if $timer <= 0;
    $timer -= tv_interval($start), redo
        if select undef, undef, undef, $timer;
}

print "*Yawn* what time is it?\n";
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This seems to work okay on Win32.

#! perl -slw
use strict;

$|++;

sub sleepFor{ 
    my @sigs = keys %SIG;
    local %SIG;
    $SIG{ $_ } = eval "sub{ print 'Got signal $_'; }" for @sigs;
    my $t = time() + $_[ 0 ]; 
    sleep 1 while time() < $t 
}

print scalar localtime;
sleepFor $ARGV[ 0 ];
print scalar localtime;

__END__
P:\test>421347 10
Tue Jan 11 18:51:06 2005
Got signal INT
Got signal INT
Got signal INT
Got signal QUIT
Got signal INT
Got signal QUIT
Got signal INT
Tue Jan 11 18:51:16 2005
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Update: I know this works with signals. I can't say my code caught a lot of them though since I avoid them as much as possible.