There  are many ways to include family and friends.  The traditional role has been to have them as attendants in your bridal party or you can invite them to ....

• Present a reading, sing a special song, or play  an instrument.
• Be the ring bearer (even if they are not in the bridal party, they can come forward when requested).
• Be witnesses for the signing of the legal certificates and register. 
• Co-ordinate the music if you are using recorded music.
• Greet and usher guests to the ceremonial area or their seats.
• Take responsibility for handing out orders of service, petals, bubbles etc.
• Be the wedding day co-ordinator - someone who has a clear picture of your vision and ensures that everything is unfolding as you would like.   This person can make decisions on your behalf.   They can introduce themselves to the celebrant, venue and reception co-ordinators, musicians, etc
• Provide support for a parent who may be attending on their own.  Your friend or family member can take them to their seats, provide them with transport from the ceremony to the reception, ask for the first dance etc. At one wedding the mother of the bride had organised so many other things and yet when it came time to go from the ceremony venue to the reception, she had to ask for a lift. It was ok, however this made her feel very uncomfortable.
  
• Be the chauffeurs. Be sure the ceremony starts after they have returned from parking the cars.