<p>of course it wouldn't hurt to send him a thank-you letter, but would it be inappropriate not to?</p>
<p>and would it be weird to call the guy and ask for his address a few days after the interview, so that i can send one?</p>
<p>I would send a thank-you email if you have his email address.</p>
<p>If the interview is over and you don't have a mailing address, you might call on the phone to thank him/her while explaining that you didn't have a mailing address. I personally would not call to ask for the mailing address.</p>
<p>you can e-mail one. do you usually get a card?</p>
<p>You can look up his phone number in google and get his address.</p>
<p>usually the admissions counselor will give you his/her card, which should have e-mail, address, etc. if they don't give you contact info., look up the office of admissions on the school's website and send it there, addressed with the person's name, of course. it's generally considered impolite if you don't make a gesture of thanks, so i would make sure that you take the extra effort to show your appreciation.</p>