D7, The Wall Street Journal’s All Things Digital Conference, kicked off in California, featuring interviews with some of the biggest names in technology.  Some of the focus this year is the near future of technology and how the latest products and updates to existing ones will be able to make money.

Some of the speakers include Twitter founders Biz Stone and Evan Williams, Steve Ballmer of Microsoft (MSFT), John Lilly of Mozilla, and Carol Bartz of Yahoo (YHOO), who spoke about her new role as CEO of the company and said she'd be willing to sell Yahoo search to Microsoft for "boatloads of money," among other things.

Bartz acknowledged that talks between the two companies are still going on.

A big highlight from the event is Plastic Logic’s new e-reader that is bigger and thinner than Amazon’s (AMZN) popular Kindle and targeted at business users. 

This device measures 8.5 inches by 11 inches, the same as the standard letter size for the paper you load into your printer at the office. 

Plastic Logic CEO Rich Archuletta told FOX Business in an interview the device will be available at the start of 2010 and that it will be able to handle all different types of content, including PDFs, Word, and Excel files.  He showed a working prototype of the device displaying a cover of Fortune magazine as well as a couple of documents.

See this interview and all the others, listed under Related Content.

Archuletta said the technology behind it, which allows it to be so thin, was developed by the lab that started the company out of Cambridge, England.  It uses transistors made of plastic, rather than the traditional silicone that’s used in almost every other display out there.

Asked about how it compares to the Kindle, he said the Kindle does a great job showing people how you can get books in a seamless manner.  

“Our product is designed for business users. So from the ground up, the whole user interface, the fact that it's a touch interface," Archuletta said. "The fact that you saw the menu on the left-hand side where you can move between documents very easily. So it's not just reading one page after the other, it's about going back and forth between documents, highlighting documents, being able to mark them up.”

Check out our Personal Technology topic page for the latest videos and articles on gadgets.

D7 began on Tuesday with an interview of the creators of Twitter, Biz Stone and Evan Williams, by Walt Mossberg and Kara Swisher of the Journal.  They spoke about the growth of the service, which was launched a year ago by Obvious Corp.

Williams said the Twitter brand has good public awareness, but the key is to turn that awareness into more engagement.  He noted that over the last 10 years he’s seen people moving their communications to more public forums such as Flickr, social networking sites, and now Twitter, and they’re getting a lot of value out of it.

Biz Stone spoke to FBN’s Brian Sullivan Wednesday morning to talk more about the possible upcoming business developments for the company. Stone said the next steps for the company include smart hiring. “We need to grow, but do it right and not hire too fast.”

Stone said one of the key features of the site is the search functionality. People around the world are reporting what’s happening and this is all public, which means this is a real time search engine that lets users look up anything that’s happening at the moment, he added.

Asked about valuation of the company, which some put at $255 million, Stone said “we're wrestling with how to value the company since we've got a web site, these apps, and other companies built on top of twitter, so in general our question is what's the most effective way to measure our success and I think we're still working on that to an extent."

And while there has been a lot of buzz about a possible Twitter reality show, Stone set the record straight. “We're not making a TV show; some other folks are working on a TV show.” He explained, “there's interest from the entertainment and news industry to create shows leveraging twitter and we say go for it, but we're not actually creating the show."

Check out Brian Sullivan's blog, as he writes and posts photos from the event.

It’s not only new brands like Twitter that are creating all the buzz at D7; long established names like Microsoft had new tricks up their sleeves as well.  Microsoft is unveiling its new search engine, which it has been testing internally under the name of kumo.com, as the company works to compete with the likes of Google (GOOG) and Yahoo in searches.

D, the All Things Digital Conference, debuted in 2003 and was created by Walt Mossberg and Kara Swisher.

The Wall Street Journal is owned by News Corporation, which also owns FOX Business.