Contact information

When you give potential future employers your contact info, you should already have a good phone number and email established so you can be easily reached, and you can keep track of your contacts with them well.

Gmail!
Just like you probably set up a separate account for dental application stuff, I'd set one up, (or even use the same one) for future dental leads.  Gmail is awesome, and you can actually forward your new account's email to one you're already using, and have it pre-labelled something easy like "Dental" when it lands in your Inbox. 

GoogleVoice!  
I'm not being compensated in any way, shape, or form for promoting GoogleVoice, but if you're already familiar with Gmail, and have an account, I STRONGLY urge you to get a GoogleVoice account and link your cell phone to a new G-Voice number.  I've been using my G-Voice number on my CV and my business cards.  Major pluses:  all your voicemails get transcribed, all calls are logged, you can call via internet hands-free from your computer (just get a headset or microphone), you can edit notes regarding each phone call, your contacts get synced with Gmail (as you add phone numbers to your contacts as you make calls; this is even more awesome if you have a smart phone like Android!), you can text other phone numbers via G-Voice instead of having to use your phone.  Just make sure you call from your G-chat, using the "Call phone" icon, and have Internet handy.  If you're not already on G-chat when you receive a phone call, you can set your account to forward the calls to your cell phone (or an additional phone if the first one doesn't pick up).

VistaPrint Business Cards!
I just recently ordered a quantity of 500 from VistaPrint for about $17 (with shipping and handling), and they just came in the mail!  They have all sorts of designs, including those specific for dental.  For safety, you should probably avoid putting your home address if you don't have a practice address yet, but I'd put at least your name, "General Dentistry", and email and phone number, so you have something to hand out in case someone is interested in contacting you in the future!

Website!
I've thought about purchasing a website domain specific for dental self-advertising, but am not really sure how I feel about this, especially when I plan on working in several different offices at the same time for a while.  If I were to purchase a domain name, it would probably be from GoDaddy.com.