Handfasting is the original "tying the knot”. It is an ancient wedding tradition which involves tying together the hands of the couple to symbolize coming together and remaining together. A cloth, cord, rope, specially embroidered cloths or handkerchiefs, and many other things can be used to bind the hands of the couple. Modern uses of handfasting are found in many religious traditions.
The handfasting ceremony is highly customizable and can be a way to incorporate special themes into your wedding day. If you prefer to include handfasting as part of a traditional wedding ceremony or if you prefer to hold a handfasting ceremony as a singular event. Handfasting can be a legal marriage in itself if particular elements are included. It is important to recognize that for handfasting to be legal, it must conform to the marriage laws of the State in which the marriage is being performed. They will have the legal paperwork and requirements taken care of at the local clerk's office or other government-specified office.
More information under the Handfasting tab and at http://weddingtraditions.about.com/od/MarriageTraditions/a/Tying-the-Knot.htm