There are actually 3 contests and/or challenges going on (2 PM official and 1 community user).
The PM "More the Merrier" for Amazon gift cards:
The PM "Community Holiday" contest where 20 winners will be receive 1 GB data:
And the "Community Spirit Challenge" put forth by the community's very own @darlicious:
Which contest? The 1GB data draw? Just need to enter your favourite holiday moment in the following thread: