Being a bit of a geek (and loving online life), I have found the emerging writers websitesa true blessing.  Today, I have written a review on the ones I am currently using.

1.  WeBook:    This is my favourite.  Suitable for anyone who enjoys reading and writing and wants to develop and take their writing seriously.  Highly Recommended.

2.  Agent Query:  The main website is a wealth of knowledge on agents and publishers.  The social site (if you can login) is suitable for anyone who is on the verge of (or is) looking for an agent or publisher.  Recommended.

3.  Authonomy:  This website has the promise of getting your manyscript on an editors desk (if shelved enough).  The members of this site take their writing very seriously and are very competitive.  It is still in beta and suffers a few bugs.  Fun concept and with use I am sure I will enjoy it more.

4.  Writers Room:  Use this website if you just write for fun and have no interst in getting published.  There are fun games to help you develop and get through writers block.  This is my least favourite site and not my cup of tea.

WeBook:  www.WeBook.com

Overall
Ranked a top 5 star!  I would recommend this site to anyone who is starting out but ready to take their writing to the next level. 

Ease of Use
This is my all time favourite.  I found the site easy to navigate and use.  There are videos you can watch with step-by-step guides, written guides or you can ask other members on the forum. 

Features
I have learnt a lot from the projects feature and had a go at P2F.  I have not yet tried AITB.  Some people feel that WeBook shouldn't charge for P2F but most competitions these days do.  I haven't tried AITB, so I can't comment on whether I think it is value for money.
a. Projects
 Members can rate (1to5 stars) submissions and leave comments to help the author improve.  You can give your work a picture and blurb and it is easy to manage and update at anytime.  A project can have more than one writer, so you can collaborate. 
b.  Page 2 Fame (Pay)
Like many writers competitions there is a fee to enter.  The difference is that submissions are voted on by the public (until the next round) and you can check how your submission is getting on - too many low scores and your out.  The prize, to have your work read by a top literacy agent (who specialises in your genre)!  There is a free comp every week on the home page and you can win free entry to P2F.
c.  Agent In The Box (Pay)
This took supports you sending out your manuscript for submission.  The fee includes feedback on making your submissiong stand out, they support you with your letter and sourcing the best agents for your genre. 

Social
Socialising is easy on WeBooks.  You can chat to people on the forums.  You can send private messages to their WeBook inbox.  You can join groups for common interests.  You can add people to your friends which helps you stay in touch with writers you like.

Agent Query:  www.agentquery.com

Overall
This is a brilliant website for finding out who is who and meeting the right people.  A very professional and well run website. 

Ease of Use
The biggest issue with this site, is how to log in?  The log in is hidden on the page and you haev to route around for 'Agent Connect'.  Once logged in, the left hand pannel is easy to navigate and use the site.

Features

a.  My Quick Connect Card
This is the cutest feature out of all the sites.  You get a piece of html code that you can add to a website or forum on another site that links directly to your Agent Query profile.
b.  My Media
Uploading your writing is easy to do, however, there does not appear to be a way of adding art work (unless embedded in your Word document),  There is no ranking or feedback system either (you can get this via the forums).
c.  Blogs
You can keep your own blog which appears on the history of your profile and in site searches.

Social
This is a profissional social website (like Linked In:  www.linkedin.com).  You can meet people via the groups (find people with similar intersts i.e. UK Writers, YA Fiction, etc) or in the Chat Room (sometimes used for industry guest speakers - tends to be USA time zone).  You can add people to your friends list (i.e. people you get on well with or a recommended agent). 

Authonomy:  www.authonomy.com

Overall
The site is developed by the editors at Haper Collins.  They can see that the world for writers is changing and so they hope with this site to identify the next big thing... online.

Ease of Use
I didn't use this site for about a month as I couldn't figure out how to use it.  I was worreid to submit anything incase I made an iditot myself. 

Features

a.  Books
when I uploaded my first book the site crashed several times in the making.  You also can't edit a part of your book, you have to go through all the steps every time you need to make a change.  You need at least 10,000 words to appear in searches.
b.  Shelf
You read other writers work.  If you think their work is good, then you add them to your shelf (this awards the books points - moving it up the charts).  You can only have 5 on your shelf at anyone time.  Books you'd like to read later can be demoted to your 'watch list' (These are like the books you don't display proudly on your shelf - but secretly enjoy).  I have had an occasion when I bug meant I couldn't add books to my shelf - I ended up with just 3 for trying to fix the bug myself.  In the end, I returned 48 hours later and was able to add 5 books again.
c. Editors Desk
The top 5 ranked books end up on the editors desk.  These books then get considered for publication.  This is a very difficult position to get to.

Social
People can comment on your work but most readers don't as although this can help your improve or boost your motivation, it won't get you any closer to the ED.  People can leave you a public message on your page, and these messages usually say 'shelved' so you can return the favour.  There is a forum but I haven't really found it very chatty.  I don't understand why, but nobody wants to be friends (something about a bug that will cause your book to lose its rank - which is not desirable).

WritingRoom:  www.WritingRoom.com

Overall
I know it is still in beta but there is a sense of it not yet being completed and nothing seems to be happening.    The site feels like a colloboration of products to be bought.

Ease of Use
The site is still in Beta.  Its pretty straight forward and all the sections are nicely laid out.  My profile is pretty much blank (probably cos I chose the expert option) but a lot of the fields on there are not needed - should just hide blank fields.

Features

a.  Writing
Upload your writing.  It is then voted for on a rating of 1 to 10.  My experience of the writing on this site has be very amature and a lot of very short pieces. 
b.  Copyright (Pay)
ProtctectRite (www.protectrite.com) is a company that can help you protect your writing.    For me, copyright is a very complext issue.  WeBook and Authonomy insist that the author retains their copyright for posted text, however, I have heard that agents do not like writers to post more than 3 chapters. 
c.  Self Publishing (Pay)
They are in partnership with Word Clay (www.wordclay.com) so you can produce and market your own book.  They also are in partnership with Inku Book (www.inkubook.com) who specialise in publishing picture books. 

Social
Personally I find that this site seems to attract younger people (who seem to be in some emotional turmoil).  I find that writers don't seem to want to read much on that site (not if the story is more than 250 words) and they don't comment much.

Raven Clark:  http://ravenclark.weebly.com/1/post/2010/05/the-language-of-writing-or-wow-was-i-green.html
This is a link to a blog by a friend I met through WeBook.  In this post, Raven compares WeBook and Authonomy lingo and his initial reaction.  Quite funny!