A Pennsylvania bar owner had to close for running illegal poker tournaments:

Prosecutors had stated that unlike pool or darts, poker is a game of chance, not skill, and games of chance are illegal outside of casinos in Harrisburg.

Poker Players Alliance links to lots of other stories like this. They are a lobbying organization trying to keep poker legal. They argue, quite convincingly in my view, that poker is a game of skill and should be treated as such. In the Pennsylvania case I started with, darts and pool tournaments are run the same way as a poker tournament; a fee is paid, the bar takes a cut and hands out the rest in prize money. The bar was not allowing gambling in which players buy chips that represent cash and can run through the rent money.

My main interest in the Poker Players Alliance does not exist yet. They plan to have a database of poker related laws in every state. For now, you have to be satisfied with a few, quite extensive, pdf articles such as this law review level article titled Poker: Public Policy, Law, Mathematics and The Future of an American Tradition.

As Card Squad notes, one immediate task for PPA is lobbying against the Unlawful Internet Gambling Enforcement Act of 2005, which would make it illegal for banking companies to work with online gaming sites.

Not everyone is excited about Poker Alliance. Poker Rules notes that most of the funding comes from online casino sites.

And that's what a new Las Vegas-based group is trying to do: Bluff that it is a grass-roots effort of kitchen-table poker players, rather than the professional lobbying effort funded by billion-dollar Web poker Goliaths that it really is.
The Poker Players Alliance says it wants to sign up tens of thousands of recreational poker players, each of whom would pay $15 in dues.
The group would lobby federal, state and local officials to help fight a potential federal ban on Internet gambling and stop raids on community poker games by state and local law enforcement officials.
But much of the seed money behind the group comes from online casinos . . . .

I am not sure that it's a bad thing but he makes an interesting argument:

The involvement of offshore poker operators could keep Las Vegas and other U.S. casino companies, wary of offending state and federal regulators, from helping out the cause.
Over the next six to 12 months, the group hopes to have signed up "tens of thousands" of poker players as members, Gorewitz said.
The alliance isn't a front for Internet poker rooms, he said. Membership fees will come from individual gamblers and not corporations.
"We need to have a real grass-roots organization," he said.
Changing state and local policies on gambling presents an even tougher challenge for the alliance, which hopes to eventually lobby on a state-by-state basis.

We have gone a surprisingly long time while poker remains mostly in a legal gray area. In the next few years, the legal landscape for poker will change rapidly. Poker Players Alliance won't be the only player but it looks to be one of big guys.