I've collected and compiled. These are the merchants (so far) who have generously set out an Advent Calendar or other daily gift for the holiday season. The gifts may not be active until 12/01/2012 and some of them don't start until later in the month.
Any details I have about the prizes are included (i.e. Advent or 12 Days of Christmas, etc.). I have attempted to get as much information as I possible can. However, I could have something listed incorrectly. Please let me know if you find errors on this list. You can drop a note down the well and I will fix it as soon as possible!
We don't normally list items costing over $1L here at Yer Mawm. Some of the shops listed here, however, do charge a nominal fee for the item or are restricted to group members only. Some of the groups do charge a fee to join. Any items that will cost lindens are clearly marked (provided that I am aware of the fees). Please be aware of this when collecting the prizes. I'll update as I have more information.
You can grab a copy of this list from Yer Mawm and Sit Here Slap This group notices should you need a copy inworld.
Should you run across others or have one at your own shop, please drop a notecard down the well and I'll get the location on this list lickety-split!
Happy Holidays and all that jazz!