Yahoo! (NASDAQ:YHOO) and privately held Google once again traded blows on Monday, but it appears this time that Yahoo! won the round, thanks in large part to its recently acquired Overture Services unit.

Time Warner's (NYSE:TWX), Disney's (NYSE:DIS), and Dow Jones' (NYSE:DJ) The Wall Street Journal Online all inked deals with Overture to supply sponsored ads that appear in search results or beside related news stories. went even further, agreeing to use Yahoo!'s Web search technology and replace Google. The news comes during a big week for Yahoo!, which on Wednesday reports first-quarter earnings.

For its part, Google says it will replace BellSouth's (NYSE:BLS) home-grown site search technology with its own. The deal is the latest in a string of wins for Google with Internet service providers (ISPs), including America Online, and could open more doors.

If anything, the various announcements demonstrate that Yahoo! and Google are increasingly stepping on each other's toes. And it's no wonder. Overture pioneered pay-per-click searches, which have become a big business expected to generate as much as $4 billion annually by 2005, according to published reports. Google and others, likeAskJeeves (NASDAQ:ASKJ), want a piece of the action.

Similarly, Google is the heavy in powering searches of corporate websites, with 130 business customers. A search of its 2003 10-K reveals no such numbers for Yahoo!, but the CNN deal demonstrates that the relationship with Overture gives it a fighting chance in corporate search. Citigroup's (NYSE:C) Salomon Smith Barney estimates powering business site searches will be a $2.6 billion market this year and could grow at 20% annually through 2008.

What does it all mean for investors? Nothing yet. This is a competition worth watching for its entertainment value. Over time, the various parries in the news may give clues as to who will dominate the market. You might try playing press release bingo with each company's announcements to get an early indicator. (Write me if you do.)

But don't expect to see investing opportunities soon. As Fools know, long-term gains in the market are rarely fueled by hype.

Time Warner is one of David Gardner's recommendations in Motley Fool Stock Advisor . To discover the others, and see which companies his brother Tom has deemed worthy, sign up for six months with a money-back guarantee.

Motley Fool contributor Tim Beyers thinks Google rocks for Web research, but he depends on Yahoo! Finance. He owns no stake in either company, or any of the firms mentioned in this story. You can view his Fool profile here.