eBizMBA has put together a pretty solid list of the Top 15 Most Popular Web 2.0 websites based on multiple data sources.  I like their definition of Web 2.0 – those being entirely based on user generated content, as a simple yet accurate way of describing this growing sector of web properties.

You can visit the full list at eBizMBA to see the data used to create the ranking.

Whether you use all or some of these sites, it is quite obvious that from an SEO perspective, having quality profiles and content on these sites will carry significant weight with Google, Yahoo and Bing for your own site.

1 | YouTube

2 | Wikipedia

3 | Blogger

4 | craigslist

5 | WordPress

6 | twitter

7 | flickr

8 | IMDB

9 | photobucket

10 | digg

11 | eHow

12 | TypePad

13 | HubPages

14 | deviantART

15 | wikia

A parting thought….I regularly use all but one of these.  Am I the only one who doesn't use deviantART!?!?