Fools were out and about this past week in an investing world jam-packed with actions and ideas. Here are three articles you might find useful as you decide how to invest your money.

The No-Brainer Natural Gas Investment?
Fool analyst Austin Smith served up an article aimed at helping the many Fools interested in investing in natural gas. First, he warns that funds investing in natural gas futures contracts might not be as good a deal as they seem. "When the price of a far-off contract exceeds that of the 'front-month' contract, these funds lose money because futures prices must move to match the spot price and therefore underperform the commodity," he explained. "However, these vehicles must sell their positions to purchase another contract further into the future to avoid actual delivery -- an unprofitable Catch-22."

Westport Innovations (Nasdaq: WPRT) is a much more straightforward play on natural gas and its rising use in commercial vehicles. The company specializes in converting diesel engines to run on natural gas. "The stock has risen 143% in the past 12 months, and it has the legs to run," Austin wrote.

Read the article for more warnings and thoughts on how to play natural gas.

Pipe Down, Euro Haters
Fool analyst John Maxfield takes readers on a tour of Europe, poking holes in the popular sentiment that the 17-member eurozone should call it a day. "[W]hile breaking up the euro makes for a great theoretical argument within academia and among political commentators, the actual disassociation would trigger severe financial and economic repercussions," John wrote.

According to John, "the ailing Continent imported $330 billion in American goods last year and served as a principal base of operations for any number of American companies." McDonald's (NYSE: MCD) gets 40% of its revenue from Europe, while Philip Morris (NYSE: PM) gets 65% and Ford (NYSE: F) gets almost 30%. "A motley bunch of undervalued currencies ... wouldn't do the American economy any favors whatsoever," John wrote.

Read the article for John's full take on why the eurozone can't just break up.

1 Revolutionary Tech Stock We Like Right Now
 Investing can be cool. Just listen to Fool analyst Jason Moser talk about the opportunity ahead of 3-D Systems (NYSE: DDD), which is in the business of 3-D printing, also called additive manufacturing. A quick trip to Wikipedia explains that 3-D printing is the process of making solid, three-dimensional objects from a digital file. Jason tells the MarketFoolery podcast audience that these objects could include a hearing aid or a smartphone cover.

"The biggest trick here is to get your mind around the actual possibilities and how this thing works," Jason said. "It's something that's really taking manufacturing to a new level," he said, and 3-D Systems is in a sweet spot of getting some 70% of its revenue from recurring sales of supplies to printer owners.

The company and the industry face some high hurdles, but there's potential.

Listen to all of what Jason had to say.

Dividend stocks are a good foundation on which to build your portfolio. To get started, read the Fool's special free report, "Secure Your Future With 9 Rock-Solid Dividend Stocks."