There are many ways that traditions are started. In my family, the tradition of opening one (and ONLY one) gift on Christmas Eve was a compromise that my parents made when they were first together. My dad, coming from an English background, always opened his gifts on Christmas morning; my Dutch mom, on the other hand, was used to staying up late on Christmas Eve for hers. So, they decided to meet (somewhat) in the middle.
When I was little, the Christmas Eve gift was always something that could be used right away - like new pyjamas, Star Wars sheets (true story), or a book. It would be just cruel to give a kid something awesome, like a bike, and then send then straight to bed, don'tcha think?
Tonight, continuing the tradition, Jake will be getting a new pair of flannel pj pants before heading off to bed. (Don't worry, he won't read this.) As soon as he is asleep and the prep for breakfast is done, I will stuff the stockings, put the big secret-special gifts under the tree, and then kick back with a snack and a glass of wine to watch the roaring yule-log on TV. I hope your evening is as peaceful and relaxing as mine. Merry Christmas!
Incidentally, the best Christmas Eve gift that I ever received was a Holly Hobbie swing-arm lamp for my nightstand, just like the one below. (This one was found in an Ebay auction for...get this...$144. Gah!)
*The awesome catalogue page at the top of this post is from this Flickr stream. If you ever have a little time to kill and you are in the mood for some nostalgia, it is definitely worth a look.