In a post-Myspace, post-Facebook world, the logical next step for online social networking is specialization. Hence the birth of niche sites like Selfportrait, which is aimed at creatively minded twenty-somethings, and Iqons, a similarly-structured domain created exclusively for the fashion-minded.

But, the evolution hasn't stopped there. There's a new way to mingle in the virtual world... that is, if you can procure an invite. Thanks to an increasing desire for filters and intimacy online, social networking sites are employing velvet-rope policies, keeping their communities small, and, in most cases, reserved for the elite. If it works in the real world (think Soho House, and, more recently, NYC's own members-only arts club, Norwood), why not online? Here, psychoPEDIA narrows down six of the newest members-only networks du jour:

Metrofunk
Launched last November, NYC-based Metrofunk has anointed itself the world’s first invite-only social network devoted entirely to nightlife, fashion, film and music. Thus, to join, you'll have to prove your association with one of those four fields (which are also the four categories into which the site is divided). Born with the intent of bringing together industry insiders-- club promoters, fashion designers, musicians and filmmakers included-- the site has the ability to create (and monetize) individually branded online social networks. The goal: those networks will later serve as grassroots distribution channels for members' own products.

Ideeli
For anyone who has ever braved a block-long line on Fifth Avenue, freezing for access to a sample sale, the concept driving Ideeli will make perfect sense. Myspace meets Portero, this members-only network, created for sartorially savvy women, centers around luxury shopping and socializing. In the website's own words, it "translates member excitement into a deeper connection with established and up-and-coming brands." Ideeli offers members discounts on accessories, access to exclusive sales, as well as perks for the fashion labels that participate. Ideeli even blends in sales alerts, as a way to discreetly sell off last season's merchandise. With the luxury market on the rise, it looks like Ideeli's timing may be ideal. Stay tuned: still in its invitation-only phaze, there is a possibility this site will open to the public in the future.

Gilt Groupe
Also new on the invite-only sample sale scene is Gilt. This members-only site offers exclusive access to sales-- which are all held online via this e-commerce site. Designer goods by fashion heavyweights like Zac Posen and Alessandro Dell'Acqua are sold, with up to three top designer sales every week. As the site puts it-- a favorite fashionista pastime now transcends the brick-and-mortar world to a computer near you.

Diamond Lounge
Based out of New Bond Street in London, this elite social networking site is geared towards the Beatrice Inn/Bungalow 8 crowd (and charges accordingly— there’s a $60 a month membership fee). In exchange, Diamond Lounge boasts benefits for those looking to socialize both for business and pleasure. And, it's even (somewhat) democratic with regard to its membership policy. Haven't received an invite and feel as though you've been unfairly slighted? Fill out an application for membership ("complete with all the reasons why you should be accepted”). Once you’re in, fill out your “lounge profile” with business vitals, body type and budget (options range from up to $100,000, to over $20 million). Do some schmoozing in the “boardroom,” or send a coworker or prospective date a gift. But, when it comes to the latter, don’t expect any teddy bear icons à la Facebook. Offerings in this uber-luxe world are more along the lines of real Gucci bags and tickets to St. Tropez.

Extravigator
This travel-centric, invite-only network is highly interactive. A destination for discerning discussions, and shared experiences, Extravigator offers readers advice and opinions on high-end travel. It boasts an online database (which can be downloaded into Google Earth), personal profile pages, photo streams, video, and an interactive map. And while members get to take part in the website’s world-class hotel, restaurant, spa, shop and food discourse, non-members can still reap rewards. Content is visible by anyone. While membership is application-only, it's free for the lucky ones admitted.

Doostang
Founded by Harvard, Stanford and MIT alums, this career-oriented invite-only network is one-of-a-kind. Post your resume and other personal information on your profile, and maintain friends via personal relationships or work affiliations. Clearly geared towards recent post-grads, this site offers a unique means of navigating job opportunities, and sharing career info with friends. Based out of Palo Alto, CA, Doostang.com doesn’t offer an application for membership; so prospective Doostangers will have to procure invites from card-carrying friends.