A few WDW Restaurants have "souvenir glasses" available for sale. Some do not. I have a nice collection myself.....
To answer your question, the SCI-FI menu offers drinks that come with a "glow in the dark ice cube", but does not mention being able to purchase a glass from there.
Over at the Liberty Tree, you can take home the Spirit of Liberty, one of the Tavern Keeper's Collector's Mugs for $5.00
Other cups are available at:
Cinderellas Roytal Table
Tony's Town Square
O'Hana
And, of course, the refillable mugs from any resort.
HAVE FUN!
:wave: