I have sold two houses long distance, across state lines with those houses in different states. You don't need to be there, unless your state has some law against it. Ask your realtor or title company
All you need to do is have the closing documents emailed to you and then notarized in front of a witness on day of closing. Email signed documents for proof of signing on appropriate day and overnight with what keys you may have. Most kinko's or ups stores have notaries and work friendly hours.