You want the LWP::UserAgent module. Here's some example code from the manpage:

 require LWP::UserAgent;
 
 my $ua = LWP::UserAgent->new;
 $ua->timeout(10);
 
 my $response = $ua->get('http://search.cpan.org/');
 
 if ($response->is_success) {
     print $response->content;  # or whatever
 }
 else {
     die $response->status_line;
 }
[download]

This will try connect to the URL 'http://search.cpan.org' and $response->is_success will be true if the HTTP GET request was successful.

As an FYI a ping is a special sort of request sent to a machine in order to determine if it is accepting network connections. It's very often used in port scanning, and many people will turn off ping response in order to make their machines appear to be down to the casual ping scanner. Lack of a ping response doesn't mean a machine is down, and existence of a ping response doesn't mean that the machine is accepting HTTP requests.

Hope that this helps. :)