Don't be afraid to approach attorneys at events, that's simply the biggest hurdle! Keep tabs on alumni events at your school. That's the easiest way to meet attorneys, especially those willing to mentor you and help you get a job. They have a vested interested in seeing that students from their school do well on the job market--it enhances the school's reputation as well as theirs. Be active in student orgs, though you don't necessarily need to be in a leadership role. Inviting attorneys to speak at events on campus is a good way to network.
If you go to events like the CLEs beaverfuzz suggested, you can approach the speakers and thank them for their presentation before casually "interviewing" them. You might research the speakers a bit beforehand so you can ask good questions. Same with conferences--if you can get an attendance list beforehand, see if anyone's coming from organizations that you're interested in working for and keep an eye out for namebadges. Of course, don't get stalkerish or get into interrogation mode, LOL