Question about post interview thank you

I had a panel interview yesterday for a new grad position and I had planned on sending thank you letters in the mail today to all interviewers. However, at the end of the interview they said I should hear something by tomorrow so I a really can't mail it out. I was either going to drop them off in person or email them. I'm not sure how I would drop them off because I don't really know where all of their offices are etc. I guess my main questions is an email considered OK now? I have never sent thank yous for jobs by email.

Any suggestions?

Thanks

I would write brief thank-yous and take them to the HR department at the institution today. But Donna Cardillo, who offers great career advice for nurses on her website, suggests that e-mail is OK if you have a very brief window of opportunity. Here's the link:

http://www.dcardillo.com/articles/followup.html