Yes, in my opinion, 2006 is the year that Web 2.0 broke - i.e. hit the mainstream. For me, the most pleasant Web 2.0 surprise has been last.fm. I’ve always been into music, mostly the alternative/indie kind, ideally fronted by women singers. After all, I used to front a band myself! Through last.fm I’m gradually expanding my music knowledge base, though I mainly concentrate on contemporary British bands (tip: The Long Blondes from Sheffield). Great stuff 
Today I finally signed up with delicious. I’ve been discussing signing up to Web 2.0 sites elsewhere (heading: Is there a Point in Signing up to MySpace?) and the bottom line is this: I don’t really think I need to participate in all the big social networking sites. E.g. I do have a digg, youtube, and flickr - account [can't be arsed to put all the links in..] and a fair few more, but don’t really use those all that much. Hence, I’m probably never going to sign up to MySpace and Beebo etc. etc. - don’t think there’s a point.
What I will do however is provide a link and bookmark it myself, with ‘The new 100 most useful sites‘ as per Guardian Technology guys, and they should know.
The second link I’m providing is a huge collection of web 2.0 resources. I haven’t looked at these in detail but the purpose, similar to the link above, is to provide something to bookmark/put into delicious and read later 
To conclude, 2006 for me is the year that web 2.0 broke. Let’s see what happens in 2007 - experts think that blogging for example is going to peak in the new year. We’ll see..
for sure, it will be really exciting to see new concepts. Different hyprids of of all these services.