Buy a fixed-rate bond, and your income stream is constant. Buy a dividend-paying stock, and there's always the chance that the distribution will grow as the company's prospects improve. That's the double bonus of companies that raise their payouts -- more money for shareholders, coupled with the company's stronger fundamentals.

Let's take a closer look at four companies that inched their payouts higher this past week.

International Game Technology (NYSE:IGT) shareholders hit the jackpot after the slot-machine giant upped its dividend from $0.12 to $0.125. Not much of a hike, you say?

Let's not look a gift half-penny in the mouth. The company has been struggling lately, with domestic sales falling in recentquarters. The marginally more potent payout should provide some degree of comfort to owners who have seen the stock shed 43% of its value since peaking in the spring of 2004. Naturally, it will take a long time to work off the stock's precipitous drop in quarterly pocket change. The thinking here is that the stock is feeling confident enough with its future prospects to the point where the shares will eventually follow suit higher.

The future's so bright for Oakley (NYSE:OO) investors that they've got to wear shades after the eyewear specialist eased up on its purse strings. Later this month, the company's annual distribution will be growing by a penny to hit $0.16 a share. It's been a good year for the company. Back in April, Oakley was targeting earnings growth for 2005 to clock in between 15% and 20%. Now the company is expecting profits to grow by 25% to 30% this year.

National Semiconductor (NYSE:NSM) is upping its quarterly ante by 50%. Then again, it should be noted that this simply means that the chip maker's payout is going from $0.02 per share to $0.03 a stub. Still, it's just another indicator that this cyclical player is coming back into favor. Last month, the company posted a respectable uptick in bookings, and that's usually a solid indicator of strength in the near term.

Drugmaker Wyeth (NYSE:WYE) was another hiker. Fueled by strength in its flagship pharmaceuticals business and the recent FDA approval of its infection-battling Tygacil drug, the company's turnaround is rewarding shareowners, who were receiving quarterly dividends of $0.23 a share. They will now be getting a full quarter, starting with next month's payout.

The move bumps up Wyeth's yield to 2.2%. Compared to some of the bigger players in pharmaceuticals, that may seem like chump change. Motley Fool Income Investor pick Merck (NYSE:MRK) yields 5.5%. Bristol-Myers Squibb (NYSE:BMY) is at 4.6%. Even Motley Fool Inside Value pick Pfizer (NYSE:PFE) has a generous dividend policy, currently yielding 3%. However, the move is notable for Wyeth, since it hadn't hiked its quarterly dividend since the 1990s.

Subscribers to our Income Investor newsletter can appreciate the companies sending more and more money to their investors. Analyst Mathew Emmert has often singled out companies that are committed to growing their distributions with market-thumping results.

Want to see what Mathew likes these days? Go ahead and give his newsletter service a shot with a 30-day trial subscription. Who knows? Maybe the next thing that will get hiked will be your interest.

Longtime Fool contributor Rick Munarriz pays attention to yield signs. He does not own shares in any of the companies mentioned in this story. The Fool has an ironclad disclosure policy. Rick is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early.