Social media guide Mashable has unveiled 15 Twitter Lists focusing on, you guessed it, social media.

Among the Mashable Twitter Lists:

Media Thinkers: media thinkers and commentators.

Social Media Linkers: social media experts, thinkers and linkers.

News Orgs: news organizations on Twitter, breaking news.

Marketing Experts: marketers who Tweet, digital marketing insights and links.

If some of these lists look a little, well, light, founder Pete Cashmore explains:

These are nowhere near finished, of course: just a starting point. We'll be adding more and more names over the coming weeks. If you see people you'd like to include (and there are many, many more to add - sorry if we missed you!), just send a Tweet to @mashable with your suggestions.

Now don't be shy, marketing experts.