Wobble, you are wrong.
The Athlon Thunderbirds are SOCKET A CPU's, not SLOTs.
So, you can do the L1 bridge multiplier trick on a Thunderbird or Duron.
It's only the original Athlons that you can get in a SLOT A configuration.  Not that you'd want to.  

I think there was some confusion there.  Lets go through the chips.
1.  Athlon.  The original, and a Slot form factor chip.
2.  Thunderbird.  The new design Athlon with a Socket form factor.
3.  The Duron.  A "value" version of the Thunderbird, competitor to the Celeron.  Also a Socket form factor.
Only the original slot A Athlons require the gold finger devices to change multipliers.  Both the new Athlons and Durons can be unlocked with the L1 bridge pencil trick.
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Sean "Lephturn" Conrad - Aces High Chief Trainer
A proud member of the mighty Flying Pigs
http://www.flyingpigs.comCheck out 
Lephturn's Aerodrome for AH articles and training info!