Ah, the Dutch tradition of Sinterklaas...
"Sinterklaas or Sint Nikolaas in Dutch or Saint Nicolas in French, is a holiday tradition in the Netherlands and Belgium (both Dutch and French speaking parts), celebrated every year on Saint Nicholas' eve December 5 or, in Belgium, the morning of December 6. The feast celebrates the name day of Saint Nicholas, patron saint of children."
I copied that first paragraph from the Wikipedia page on Sinterklaas. Please read the rest of the article on the tradition on that page since in my opinion it covers it completely and thoroughly. At least better than I would be able to do in a simple blog post.
Something interesting that the article only briefly mentions is that Sinterklaas is also the basis of the present day Santa Claus. "Santa Claus" is actually a simple mispronunciation of the Dutch word "Sinterklaas" by the English settlers of New Amsterdam (later renamed New York). Children placed (and to this day still do) their straw filled shoes at the chimney every winter night, and Saint Nicholas (who, unlike Santa, is still riding a horse) rewards them with candy and gifts which - after the British seizure of New Amsterdam in the 17th century - evolved into the current Christmas tradition of hanging socks or stockings at the fireplace.
Since in the Netherlands the giving of presents is Sinterklaas's job, presents are traditionally not given at Christmas, but commercialism is starting to tap into this market (and since my dad is a retailer I can't rightfully say that I don't approve of that on some level...*smile*).
In the Netherlands presents given during Sinterklaas are often accompanied by poems, sometimes fairly basic, sometimes quite elaborate pieces of art that mock events in the past year relating to the recipient (who is thus at the receiving end in more than one sense). The gifts themselves may be just an excuse for the wrapping, which can also be quite elaborate. Just ask Rachel and Rebecca after the House Church Christmas party... ;-)
A tip if you are ever in the Netherlands in the 4 to 6 weeks prior to December 5: try to see if you can catch the 'arrival of Sinterklaas' in the city you are visiting. It's quite the show. For those of you with a broadband connection, just type in 'Sinterklaas' on YouTube.com and you'll see what I'm talking about...