According to Favor Facts: “Middle Eastern wedding favor tradition is centered around the Jordan almond. A candy-coated nut supposedly representing both the bitter and the sweet of marriage, custom dictates that you give five pieces to each guest, to represent the five wedding wishes: health, wealth, happiness, fertility and longevity.”
According to the package of Jordan Almonds I picked up today: “Wedding favors date back to Victorian times. Sweet wedding favors were created in the odd numbers of 3 and 5. Favors with 3 sweets symbolized health, wealth, and happiness. Favors with 5 sweets, symbolized health, wealth, happiness, and one each for a boy and a girl.”
eHow explains How to Make Confetti or Almond Favors for an Italian Wedding: “Buy enough candy for all your guests. One Italian wedding tradition dictates that 5 almonds be given to each guest to symbolize health, wealth, happiness, fertility and long life.”
The most descriptive site is CandyFavorites, which gives a Brief History of Jordan Almonds (AKA Confetti): “White for weddings, Silver for twenty-fifth anniversaries, Sky-Blue or Pink for christenings, Red for graduations, Green for engagements… smooth, textured, spherical, oval, teardrop, heart-shaped… with centers of almonds, hazelnuts, anise seeds, cinnamon sticks, rosolio (a sweet old-fashioned liquor made of Tangerines), coffee beans, peanuts, pistachios, marzipan, chocolate… in party favors, flower arrangements, fruits baskets and other constructions of the confectioner's art and imagination. These are just a few of the myriad colors, tastes and shapes of Italian confetti, also known in the “new world” as Jordan Almonds, which are those little sugar-coated candies present at every important occasion in Italian life.”
The Knot ties it together with a short and sweet (no pun intended) Jordan Almond symbolism breakdown: “Jordan Almonds make great wedding favors — wrap a cluster in tulle tied with ribbon, pack a few in boxes (made of sugar, straw, paper, metal, or plastic), stuff some in decorative bags, or pour a handful into champagne glasses or glass bowls. Attach a little card with a note explaining the almonds' meaning (so guests know they're not just an intermezzo between the salad and the entree). How to? Consider using the Jordan Almonds poem.”

Jordan Almonds for Thee
Five sugared almonds for each guest to eat
To remind us that life is both bitter and sweet.
Five wishes for the new husband and wife -
Health, wealth, happiness, children, and a long life!

All I know is that I've had Jordan Almonds at every Italian wedding to date. Not at the wedding, per se – but certainly at the reception(s). My brother's second reception is coming up in June, I think (although I'm not sure if I'll be able to make it back as we'll be knee-deep in Gnomedex stuff by then). Ponzi and I are still deciding how our wedding will go down, although I think we've settled on a 20s/30s/40s theme somewhere in Seattle on 11/11/2006.