In short: article about buying coins at face value; no shipping charges = using credit card companies to get frequent flier miles, then paying them off with said coins.
And the pickles part:

Well played.
And the pickles part:
One FlyerTalker, identified by his online moniker, Mr. Pickles, claims to have bought $800,000 in coins. He posted pictures of the loot on FlyerTalk. He says his largest single deposit was $70,000 in $1 coins. He used several banks and numerous credit cards. He earned enough miles to put him over two million total at AMR Corp.'s American Airlines, giving him lifetime platinum-elite status -- early availability of upgrades for life and other perks on American and its partners around the world. He also pumped miles into his account at UAL Corp.'s United Airlines and points into his Starwood Preferred Guest program account.

Well played.
