Diversification can be so much fun.

IBM (NYSE: IBM) is on a Big Blue roll. Last night, the company destroyed Wall Street estimates with $3.09 of adjusted earnings per share on $26.7 billion in sales. Putting the "international" in International Business Machines, more than half of the year-over-year revenue growth came from positive currency adjustments.

Economists may worry that issues in Greece and Portugal could wipe out the euro, but that currency has more than held its own against a flagging dollar in recent months. Our greenbacks are also declining against other important international currencies, such as the Japanese yen. And IBM is taking all of that action straight to the bank.

In fact, those tremendous currency gains could become a serious drag if the dollar ever stages a real comeback. The Americas lagged EMEA and Asia-Pacific in sales growth in GAAP terms but actually shot ahead under constant-currency accounting. Since much of the foreign revenue is staying overseas to avoid a tax hit at the border, some of these gains are reversible if the global-economy focus shifts back to America.

IBM reaped 58% of its sales outside the Americas, which gives Big Blue a much heavier international focus than Oracle's (Nasdaq: ORCL) 49%. Hewlett-Packard (NYSE: HPQ) had 56% of last quarter's revenues collected in North and South America.

So keep this domestic-international split in mind if you're at all interested in dollar-rate moves. And of course, it's not all risk. If you see the dollar staying weak or maybe getting even softer, then it's a terrific attribute.

HP and IBM could actually make a comfortable home in our Global Gains portfolio right next to the more obvious non-Americans. The team behind that newsletter has already handpicked a few down-home companies, including Yahoo! (Nasdaq: YHOO) and Yum! Brands (NYSE: YUM) thanks to their substantial overseas exposure, so picking IBM as an international investment wouldn't be a completely unprecedented move.

Keep track of Big Blue's moves around the globe. Our Foolish watchlist will keep you connected to a steady flow of news and analysis on IBM or any other stock.

Fool contributor Anders Bylund holds no position in any of the companies discussed here. The Motley Fool owns shares of Yahoo!, Oracle, Yum! Brands, and IBM Motley Fool newsletter services have recommended buying shares of Yahoo! and Yum! Brands. Yes, we like exclamation points! Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. You can check out Anders' holdings and a concise bio, follow him on Twitter or Google+, or peruse our Foolish disclosure policy.