If you see someone on a large tricycle fitted with tall cameras pedaling your way, don't panic. It's probably a member of the Google Maps team snapping pictures for a new 3-D view of local streets. The group has been pedaling furiously around the globe since the search giant launched the Street View feature in 2007.

Since August last year, Google Maps mobile users have swelled from 100 million to some 200 million. And that's just one of many mouse clicks in Google Inc.'s growth story the past few years -- much of that fueled by acquisitions. Take YouTube, which Google bought for $1.65 billion in 2006: It's now clocking 48 hours of video upload a minute and 3 billion views a day, up from 50% a year ago, according to analysts.

Android, one of Google's most successful acquisitions, now commands a 52.5% market share in smartphone operating systems, compared with a 15% share for Apple Inc.'s iOS. Anxious to keep its entrepreneurial edge even as it's grown into one of the biggest companies by market capitalization in the U.S., Google has amped up its acquisitions the past two years -- it has chewed through 54 of them at $14.5 billion this year, its busiest yet, according to Dealogic.

That includes the $13.5 billion pending purchase of Motorola Mobility Holdings Inc., though the tally doesn't include the price tag for 28 mostly small acquisitions and startups purchased for undisclosed terms. Last year, it snapped up 46 deals for $3 billion. Bottom line, Google is the single most acquisitive company in the tech space today, based on number of deals. It has bought 116 companies since 2008, which compares with 44 for IBM Corp., the next most acquisitive among the top 15 most active tech companies.

And judging by the upbeat mood of Google's deal team, the acquisition streak seems far from over. David Lawee, vice president of corporate development at the Mountain View, Calif., headquarters, sees no shortage of opportunities. "I have never seen as many explosive areas of growth in the digital economy as today, and I've been working in this space since 1994," he says. "It's never been a more exciting time." He adds that there are "a lot of big companies and smaller companies finding ways to make money. We're very opportunity-rich."

The biggest challenge for Lawee, a career entrepreneur before joining Google four years ago, is actually digging through all those opportunities. "Finding the next Andy Rubin -- that's hard," he says of the co-founder of Android, a company Google bought in 2005 when it was a startup. To find the Rubins of the world involves scrolling through roughly a thousand e-mails a day, hundreds of them deal pitches. "It's hard from the outside to predict what's going to be interesting for Google, so I tell people it's better for me to be a filter." He speaks with some 100 people in the company and further 100 outside it to plumb ideas each quarter.

Lawee and his team of 25 (half on deals, half on integration) are so busy they tend to catch up by running into each other in the halls. They work closely with product and engineering teams to "collectively form a view" about "which companies are doing the most interesting things in the spaces around us." They have a working list they look at roughly every month. "Hopefully, you're hearing about things before they become super popular and everyone hears about it," he says.

Mostly, Lawee is on the road, scoping deals and building relationships, like the one he developed with Omar Hamoui, founder and CEO of AdMob, whom he met through Jim Goetz, a partner at Sequoia Capital and an early AdMob investor. Google acquired the company in 2009 for $750 million. "I had breakfast with them two to three times a year for three years, so by the time we did the transaction we were already friends," he says, noting how that "translated into better integration." The goal is to keep innovation at Google going strong. "Innovation is the ultimate solution for slowing growth," says Josh Olson, an analyst with Edward Jones. "Management will continue to support that culture," he says, and that helps keep them fresh.

"You have to meet a lot of people and go to a lot of meetings," Lawee says. "Then you meet an awesome person and their team, and you think, this can be huge -- you get so excited. That's the juice. That's what this job is all about."