I've yet to see one, really. ;) - l0ckergn0me

Thank you Allen! Maybe I should add a 'mainstream' tag ;-) - Orli Yakuel

Facebook, MySpace, Youtube, Google Maps - Mark Trapp

Is eBay web 2.0-ish? - Hutch Carpenter

Is Amazon Web 2.0ish? - Chrimmus Tad

That's what makes this question loaded, Hutch. If eBay was created in this decade, it would totally count. But since it was in dotcom boom, it doesn't. Or what about AIM? MSN Messenger? Yahoo Messenger? The concept of socialness on the web is not lost on the mainstream. It's just that most of the current crop of products are either too immature or just plain suck. - Mark Trapp

Mark - yup. eBay is user generated, with a real revenue model. It even has community based ratings and stuff. It's got the web 2.0 guts. - Hutch Carpenter

Agree with Facebook, MySpace, YouTube. I'd add Blogs as another 2.0 winner. I'd put eBay and Amazon as 1.0 success stories. - AJ Kohn

Facebook, YouTube - Mike Doeff

AJ, that's a good point. But I wonder...are all web companies that start in 2008 going to be considered web 2.0, even if they don't have the user generated, social elements? - Hutch Carpenter

MySpace and Youtube.... pEopLE wHo tYpE LiKe tHiS, people still on dial-up, grandmothers, the entertainment industry... everyone knows both myspace and youtube. if that's not mainstream, i don't know what is.... - Mona Nomura

Can FriendFeed ever go mainstream if the services it aggregates haven’t gone mainstream? - Kerem Ozkan

Kerem - I think so. People will do a lot more direct posting here. Direct post comments. And directly submit URLs from websites, either via the bookmarklet or a button websites will add in the future: "Share this article on FriendFeed". - Hutch Carpenter

A better way to ask this is "which web services since 2000 have gone mainstream?" Blogger. Flickr. Gmail. Facebook. MySpace. Digg. YouTube. Wordpress. Live Spaces. etc. etc. - Robert Scoble

so here's an issue with FF - i show FF comments on CN but since ya'all commented on the twitter post - they don't show on the story on CN - hmm... - Allen Stern

Blogger does not count as web2.0 - Stefan Hayden