LW will connect you as an ultrapeer if the network needs ultrapeers, if you're not firewalled & if you have a reasonably fast connection.

There's more info about it here
http://basis.gnufu.net/gnufu/index.p...s_really_short

and in this thread, though some if it's really old
http://www.gnutellaforums.com/showth...ight=ultrapeer