Here we go!
$lsid = LS::ID->new(
$locator = LS::Locator->new();
$authority = $locator->resolveAuthority($lsid);
$resource = $authority->getResource($lsid);
$data = $resource->getMetadata();
$response_filehandle = $data->response;
Voila! You hopefully have a bunch of RDF on your screen right now. Sure, that's a couple more lines than LWP::Simple, but some of that could be better encapsulated, so it really is only one or two lines more code than trying to do a GET... and with all sorts of benefits!
Oh! And here's how you get the LSID code from sourceforge. Get yourself a copy of Subversion, then cleck-out the code using subversion as so:
svn co http://lsids.svn.sourceforge.net/svnroot/lsids/trunk/lsid-perl lsids
(windows users will have a nice GUI for this)
Note that the sourceforge site indicates that it should be https://, but it works just as well as http, so you don't have to re-install Subversion to make it SSL compliant.