Formal wedding etiquette highly encourages wedding favors, since they usually serve as a token for your guests to remember your wedding-day celebration. Are they practical though? You'd be hard-pressed to find many modern, economical brides that find them essential. That being said, the appropriate wedding favor is entirely dependent on your venue, theme, personality and budget. From personal experience, the most memorable wedding favors I have seen have always been edible! I attended a friend's wedding last summer and the couple presented cans of homemade applesauce as their favor - it was the groom's late-grandmother's recipe! I'm a sucker for sentimental touches, so this favor stuck out to me as being special. It's personal details like this one that really helps define the event. Also, it was delicious!
