Schwag
All proeeds go to benefit the Language Creation Society.
We have tshirts, mugs, and stamps with the LCC and Conlang Flag logos.
You can also see a list of interesting books
for conlangers, recommended by the community - either about conlangs, using them, or inspirational in the craft.
You can add your own recommendations to this list by going to Amazon and tagging a book "conlangs" (with an s).
You should also take a look at Donald Boozer's list, Conlangs in Literature, Movies, and TV.
Note: the LCS does not officially have any position either Zazzle or Amazon, or any of the books recommended by community members.
You may also be interested in getting a Conlang Flag.