Fantasy novels often have a squire receiving spurs when he or she becomes a knight. However, the most common vision of the knighthood ceremony involves "dubbing" with a sword.
The spurs, however, were the actual symbol of knighthood. The spurs received in the ceremony were highly ornate and decorative (and probably worn only during tournaments due). A knight's spurs were gold, or at least gilt (his squire wore silver). Spurs were sometimes taken as trophies and if a knight was disgraced, his spurs would be deliberately broken. In some countries a knight who forgot to take his spurs off before entering a church (thus potentially damaging the floor) had to pay a fine to the church.
Modern cowboys often still wear highly ornate spurs at shows, although silver is a more common decoration than gilt. (In fact, some of these decorative spurs are short and have very blunt rowels, and are not really there to encourage the horse so much as to look good).
As a side note, some motorcycle clubs award decorative spurs to their members, continuing the tradition of earning one's spurs.