Here is how to format a url to create a qicklink to get invited on Linkedin. The parameter "firstname" in the url contain the string who is displayed on the Linkedin invite page.
You may want to help OpenNetworkers to connect you by providing your email address in that field. Note that a space in an encoded url is type as %20 .
<a href="http://www.linkedin.com/inviteFromProfile?from=profile&key=4367336&firstName=Yann%20(yann(at)e-soft.ca)&lastName=de%20Champlain" target="_blank">Join my Linkedin Network</a>
Join my Linkedin Network
I personnaly also use a dns alias entry to simplify this. But it required a bit more knowledge and tools. It make have a url like http://invitelinkedin.yanndechamplain.com/