Don't worry about giving them yours (unless they ask).
            
Just make sure you have their contact information.
            
In fact, you should get into the habit of doing this for every new person you meet, wherever and however you meet them.
            
Met a friend of a friend at a pool party who works in a charity?
            
Ask for her card.
            
("It sounds interesting, what you do, and I'd love to ask a question or two offline. Do you have a card I could take?")
            
Just had an interesting conversation at a professional conference with your counterpart from another organization?
            
Ask for their card.
            
Met your boss's boss, to talk with them about the office Christmas party? (I.e. you took my advice from another email and volunteered for the committee.)
            
Ask for their card -- so you can keep them in the loop.
            
Make it your new rule that you'll never shake someone's hand to say goodbye until you've asked for their card first.
            
If you do, you'll amass a lot of business cards.
            
Now, what are you going to do with them all?
            
Simple:
            
Use their email address to look them up and add them on LinkedIn (request with a friendly note instead of that terrible default message).
            
It doesn't matter if they barely know you.
            
Most people will say "yes", and when they're part of your network, they'll see every status update or blog that you post -- giving you excellent visibility.
            
Next week, I'm going to share some ideas for how you can really leverage this advantage and use it to create new job opportunities for yourself.