Is it possible for a character to make a bluff check to distract an opponent so as to make it flat footed for other party members?
You don't make a Bluff check to make them flat-footed at all. Combatants are only "flat-footed" at the start of combat before their first turn. Never after.
What you can do is use a feint (see the Bluff skill). Roll a Bluff check to make one opponent lose his DEX bonus to AC but only against YOUR next attack - not against anybody else's attacks and not against more than one attack from you.
The other thing you can do is use a Bluff check to create a diversion so that you can then dive for cover/concealment and try to use Stealth to hide from that guy. If that is successful, you can (probably, there is debate on this) use Stealth to attack him (in a later round) while he is denied his DEX bonus to AC from YOUR attack. Still only you.
Finally, as James said, you can use Greater Feint to actually get what you want - causing an opponent to lose his DEX bonus to AC until your next turn (which means that all your allies can attack him without his DEX bonus too). Note that he is still not flat-footed, but he is denied his DEX bonus vs. all attacks that round.
Note that for this to work you'll need to invest in three feats, you need to be adjacent to this enemy (or at least able to threaten him with a melee weapon), and you'll need to use your Bluff check as a move action (no full attack for you), and the opponent needs to have an INT score (and if it's very low you take penalties on your Bluff check; even just trying this against a non-humanoid causes you a penalty).
Is it possible for a character to make a bluff check to distract an opponent so as to make it flat footed for other party members?
Shatter Defenses is the closest I know to what you want. They become flat footed to you only, but requires them to be shaken, frightened, or panicked first. For that, use Dazzling Display to make them shaken.
Another option is to use the Combat Maneuver to blind them, causing them to loose Dex to AC to everyone.
/cevah
What exactly is the difference between "flat footed" and "denied dexterity bonus". Are they not the same things?
Flat-Footed: At the start of a battle, before you have had a chance to act (specifically, before your first regular turn in the initiative order), you are flat-footed. You can't use your Dexterity bonus to AC (if any) while flat-footed. Barbarians and rogues of high enough level have the uncanny dodge extraordinary ability, which means that they cannot be caught flat-footed. Characters with uncanny dodge retain their Dexterity bonus to their AC and can make attacks of opportunity before they have acted in the first round of combat. A flat-footed character can't make attacks of opportunity, unless he has the Combat Reflexes feat.
Being denied Dex bonus to AC is part of being Flat-Footed. However, being Flat-Footed includes more than just being denied Dex bonus to AC.
How about this plan:
I use bluff to distract an opponent and the party's rogue uses this as a diversion to use Stealth. Then she attacks from stealth and sneak attacks the opponent.
Is this allowable?
Some GMs may allow a circumstantial bonus on the stealth check. Others won't. There are no special rules for that particular situation.