May is upon us, and with it the onset of wedding season. Yes, it's that time of year when happy couples decide to make it official -- but can the knot be tied in an environmentally friendly fashion? Traditional weddings are often highly resource-intensive, from the invitations you send to the transportation used to bring your nearest and dearest together to celebrate the occasion. But committed enviros can use weddings to make a difference: With the average ceremony costing $20,000 (egad!), it's a great opportunity to support markets for local, organic, recycled, and recyclable goods. Suzanne Gerber of the Green Guide offers the latest advice on how to have an eco-friendly wedding, in Earthly Possessions on the Grist Magazine website.