Sometimes I am asked if a friend can officiate the wedding. Most states require that a person who officiates a wedding be a minister or judge. That officiant also must be registered to perform weddings in the place the wedding is done. The registration process is sometimes difficult and has legal issues. I have read on some web pages that you can have a friend "ordained" on the web, register, then perform the ceremony. That is a lot of paper work and risky at times so I offer to allow the friend participate in the ceremony avoiding the need to become a minister for a day. I find that when family and friends help out in a ceremony by either being a reader or master of ceremonies that the audience is more attentive. Just me standing there reciting things is not as entertaining as having a dear friend stand up and read a poem or tell a story. Grandparents are wonderful at that sort of thing. I do not think going through the paper work of an ordination for a day is necessary. The friend or family member can participate and assist in the ceremony and no risky web page ordination is necessary. I often tell couples be sure that the person doing the ceremony is registered and capable to avoid future issues like learning the friend gets too nervous to speak or somehow discover the marriage was not legal. As I am a professional wedding officiant I do not assist in having people ordained on the web to perform a friend's ceremony. That is what I do, weddings, for a living. A friend can assist in the service if the couple desires they have a part to play.
A recent news article says to be cautious with having a friend be ordained simply to do a friends wedding, it may not be legal see: http://www.nytimes.com/2012/11/18/fashion/weddings/making-sure-that-online-officiant-is-legal.html