Add HP Labs.

www/sponsors.html

@@ -25,6 +25,7 @@ of emulab.
 <li> <a href = "http://www.research.utah.edu/">The University of Utah</a>
 <li> <a href = "http://www.compaq.com/">Compaq</a>,
         especially Compaq SRC and WRL.
+<li> <a href = "http://www.hpl.hp.com/">HP Labs</a>
 <li> <a href = "http://research.microsoft.com/">Microsoft Research</a>
 <li> <a href = "http://www.novell.com/">Novell</a>
 <li> <a href = "http://www.nortel.com/">Nortel Networks</a>