Furby Easter Eggs
Contact me or add a note to the discussion group if you find any hidden secrets!
Someone reported that you can use a video recorder to 'see' the IR data streaming from the furby.  That little piece of advice has proven VERY helpful to me!
Thanks to the Trainer's Guide and Jessica for most of the following eggs:

Personality Swap
Can't confirm or deny this one, but it raises a lot of questions.

Torture
Haven't tested this yet, but you've got to read it! Furby Torture by NoraaRekab@aol.com.

Rooster
Cover his eyes 3 times(wait for him to respond each time), then pat his back.

Name
Tickle his tummy 3 times.  Pet his back.

Twinkle-Twinkle Little Star
Clap 3 times and pet his back.

Hiccups
Rock him slowly side to side.

Burps
Feed him 3 times, then pat him on the back.  8 BURPS!

'Spanish Furby'
[Not sure I buy this one]
One user reported that a Furby went "Spanish" after a reset.  After another reset, it went back to normal.  I experienced this also. Working with furby Noo-Loo, I found that when you reset a Furby, it will usually yawn, then say "cock-a-doodle-doo" before telling its name.  Once in a while it says something different.  IF THE FIRST WORD YOUR FURBY SAYS IS "BUENO" (Spanish for "GOOD") YOU HAVE  FOUND THE SPANISH EASTER EGG.  Your furby will now act "Spanish" until you reset it again.
- Milo Tsukroff