Ripped these out of a magazine I brought on a flight - Marie Claire (July 2009)
Tips for Personal Business Cards (by Leslie Barrie):
1. Use your last job title. Never anything "cutsie" like Chief Idea Officer.
2. Don't list more than one phone number.
3. Stick with simple cards. But not the free ones that give away they're free.
Don't Twitter Yourself Out of a Job (by Mina Shaghaghi):
1. Keep your politics private.
2. Never Twitter or update a status to criticize your job.
3. If not part of your job, only Twitter at lunch. Work ethic might be questioned with frequent updates during workday.