Exchange-traded funds offer a convenient way to invest in sectors or niches that interest you. If you're looking for significant dividend payers and also want to diversify your portfolio internationally, the iShares Dow Jones International Select Dividend ETF (NYSE: IDV) could save you a lot of trouble. Instead of trying to figure out which companies will perform best, you can use this ETF to invest in lots of them simultaneously. It recently yielded a solid 5%.

The basics
ETFs often sport lower expense ratios than their mutual fund cousins. The iShares ETF's expense ratio -- its annual fee -- is a relatively low 0.50%.

This ETF has performed reasonably well in its short life, beating the S&P 500, on average, over the past three years. As with most investments, of course, we can't expect outstanding performances in every quarter or year. Investors with conviction need to wait for their holdings to deliver.

What's in it?
Plenty of international dividend payers had strong performances over the past year. Western Gas Partners L.P. (NYSE: WES), for example, surged 40%, and yields close to 4%. It has been posting double-digit annualized gains in revenue and earnings over the past few years. SeaDrill (Nasdaq: SDRL), meanwhile, gained 12%. One of the world's largest oil and gas offshore drillers, it operates in the most profitable deepwater drilling regions, among other locations. Its CEO expects daily drilling rates to rise, as well. It recently yielded a whopping 8.5%.

Other companies didn't do as well last year, but could see their fortunes change in the coming years. Telefonica (NYSE: TEF), down 25%, is trading near a 52-week low and yielding close to 10%. The telecommunications company based in Spain and operating in Europe and Latin America is pressured by Europe's financial troubles, and some worry about a possible dividend cut. Still, its Latin American operations are promising, though they may not make up for Europe's slowdown.

Financial services company Principal Financial Group (NYSE: PFG) shed 6%, recently posting disappointing earnings and a drop in revenue. The company recently announced a small buyback program, and is boosting its presence in developing markets such as Brazil.

The big picture
A well-chosen ETF can grant you instant diversification across any industry or group of companies -- and make investing in and profiting from it that much easier. Learn about the 5 ETFs That Could Soar in 2012. And if you're looking for some great investments beyond ETFs, consider these 12 Dividend Stocks for 2012.