By Ethan Lyon, Senior Writer

As entrepreneurs and industry leaders adapt to the digital world, innovation is central to success. To illustrate innovation and entrepreneurship in the tech sector, we’ve selected ten companies across five categories that have secured venture capital (VC) investment. These companies are pioneering innovation and leading the next evolution in e-commerce, marketing, online video, social media and mobile technology:

1. e-Commerce

Twitter mashups are everywhere. Social media juggernaut, Facebook hosts forums that combine online video streams and real-time discussion. Established and emerging entrepreneurs are constantly creating mashup platforms in an effort to engage new audiences. Integration and convergence are re-shaping the way we interact and engage in online shopping and social activities.

oneTXT, which received $2 million in series A venture capital investment from KPG Ventures, is integrating e-commerce with social networks, participation TV shows and online games. With social shopping sites like Snipi, entrepreneurs are trying to incorporate e-commerce in new ways–that go beyond traditional e-commerce sites like Amazon. Bridgevine, a shopping engine, just received $3.5 million in series C round of venture capital investment from Constellation Ventures and Safeguard Scientifics. Mashups are key as entrepreneurs pioneer the next era in e-commerce.

2. Marketing

Mobile and in-house marketing are two—of the many—strategies leading the next frontier of digital advertising. ClickFuel, which landed $2.5 million in its first round of institutional VC funding, provides business owners tools to run their own search marketing campaigns. Search optimization tools such as those provided by ClickFuel will help business owners seeking to boost their online presence and leverage in-house employees.

AdWhirl has capitalized on the popularity of smart phones to offer advertisers a high-impact delivery system for iPhone apps and other 2G and 3G mobile devices. AdWhirl has secured $1 million in early VC funding, led by Foundation Capital.

3. Video

Online video is growing by leaps and bounds. Video consumption is expected to account for more than half of all internet traffic by 2012. Expect online video to increase in quality (e.g. YouTube now offers HD video) and delivery and management systems to add some organization to users video libraries. Nokeena, which secured $6.5 million in its second round of institutional VC investment from the Mayfield Fund, offers providers storage for high-quality video and video monetization opportunities. To manage video libraries, Grab Networks has developed an “end-to-end, automated platform” for users. Grab Networks has secured $12 million in venture equity and debt financing—led by Horizon Technology Finance.

4. Social Media

Bebo, DeviantArt, Friendster, Gather, MySpace, LinkedIn, etc, and the list goes on. Seemingly endless social networks have sprung up to gather and engage niche online communities. Often times, internet users have two, three or ten or more profiles on various social sites. To find connectedness amongst various social networks, Collecta, securing $1.85 million in VC funding, is a search engine that monitors streams of popular sites, blogs and social media. In essence it’s a digital manager—important in a world with endless RSS feeds and millions of community members.

Google Wave has garnered much attention not only because it is a Google product, but because it revolutionizes the way we view our inbox. Cc:Betty, securing $1.5 million in VC financing by Venrock, follows similar thinking in that they provide users an e-mail assistant to facilitate collaboration and aggregate like-minded users into communities.

5. Mobile

We are spending more and more time with our phones. As smart phones increase in popularity, a mobile phone is not just a phone. It’s a GPS, gateway to all social networks, internet connection and BOKU envisions it to be payment tool. BOKU, which has secured $13 million in institutional VC funding from Benchmark Capital, seeks to make online payments easier from a mobile device.