A little while ago I was browsing through the Sims Store, and I noticed several free Lord Sponge items.  (These items are free for you to purchase, but not free for your Sims to buy.)   There are four Lord Sponge items that I was able to find.  A small tabletop sculpture, a larger floor sculpture, a computer, and a series of white t-shirts with Lord Sponge emblazoned upon them. 

Here is a picture of the three Lord Sponge items in action:

Many people theorize that Lord Sponge is actually a Spongebob rip-off, which certainly seems plausible.  However, a commenter on a SimPrograms.com post claimed that Lord Sponge is the mascot of nasza-klasa.pl, which is a Polish social networking site.  This turns out to be true, and even more confusing than "Spongebob rip-off."

(By the way, it's a little annoying how you have to poke through every item in the store to find the free stuff - would it kill them to have a "Free Download" section?  They have a Free Stuff page, but it's just screen savers and computer wallpaper, no in-game items are listed there.)

The Lord Sponge computer has all the same computer-y type interactions.  In other words, there isn't a special Lord Sponge feature.  Which is too bad - I was hoping you would at least be able to use the Lord Sponge computer to "Find out who Lord Sponge is." 

The two sculptures have no available interactions, not even the "View" option which you usually get with sculptures.