China's leading search engine is hungry for more.

Baidu (Nasdaq: BIDU) revealed last week that it is taking a meaty $306 million stake in fast-growing travel search site Qunar. The news came just days after it expanded its strategic agreement with China Real Estate Information (Nasdaq: CRIC) to beef up its real estate content. China's Techweb is reporting this week that Baidu is working on a proprietary mobile operating system.

Travel? Realty? Smartphone software? Has China's top search site become a jack of all trades?

Let's be fair. The mobile operating system chatter is strictly conjecture at this point. Besides, even if it did go that route, it shouldn't surprise anyone given Google's (Nasdaq: GOOG) success with Android. Ironically enough, the Techweb rumor claims that Baidu's building its mobile platform on top of Android.

Mobile search is a big part of running a search engine these days, so why not play a bigger role?

As for the real estate play, this is another smart move by Baidu. It doesn't need to reinvent the wheel. Just as it inked a deal this month with Bitauto (Nasdaq: BITA) for automotive content, Baidu's magnetic appeal affords it the luxury of partnering with best of breed niche specialists to fortify its offerings and reach out to advertisers.

Snapping up a chunky stake in Qunar is more interesting, but isn't it simply following Google's footsteps? Google turned heads by investing even more in travel through its proposed purchase of ITA Software last year.

Skeptics may wonder if Baidu is gearing up to take on China's Ctrip (Nasdaq: CTRP) or eLong (Nasdaq: LONG), but they're ultimately missing the point. Baidu simply wants to make sure that it's at the very center of the online experience in China. If folks are searching for travel or browsing on their phones, Baidu doesn't want to be left out.

When you're the top dog in the world's most populous nation, you can never do too much to make sure you stay there.

Is Baidu trying to do too much? Share your thoughts in the comment box below.