miker71 said:

I can't think of anything where the prequels have affected the culture to the extent the OT has (e.g. R2-D2 mailbox, Tom Tom SatNav voices, Trash Compactor book-ends, etc etc).

Yes, the prequels have influenced the Fox media (Simpsons, South Park etc) and generated a ton of short-lived merchandise, but that alone does not qualify as pop culture in my book - just narrow self-serving revenue generation, little "culture".

In the real world there's just no enthusiasm for the prequels amongst everyday people. The opposite was true with the OT and it's really hard to describe to people who weren't even born back then.

Maybe we should really limit this to movies (and possibly TV), as there certainly has been a visible impact in INTERNET CULTURE.

Various youtube spoofs (like the pretty hilarious Star Wars rap), memes (unlimited power, NOOO), and the like.
The "Ackbar talkshow" has Boba Fett talk in a prequel/SE voice ;)

PLINKETT REVIEWS!!!!!!!
MTV movie awards spoof, I guess, too.
The Insult Dog at the Clones premier...
Everyone will probably recognize the Jar Jar Binks, too.
Jedis in Desert Robes are due to the prequels.

Hell, of all the bland/bad movies out there, the prequels must be some of the most famous, and most widely despised, so OBVIOUSLY it has an influence in this sense.

So there's plenty of that kinda stuff, but I think I haven't seen any of those Simpsons/South Park spoofs (which episodes would that be), or in any movie I can think of since then.