Daily (or more)
Gmail (via Entourage usually)
Squarespace (blog and website ASP)
Wikipedia (reader, not writer)
SmugMug (a commercial variant of Flickr)
NWA online flight booking
I can use on Pain of Death
All things considered, I expect I am a fairly moderate user of Web2.0-ish tools compared to most tech bloggers, at least one standard deviation from the norm of most educators. And like most of us, I see more and more of what I do move online, especially when using highly-portable devices like the XO and ASUS Eee. And I don't see the direction changing.
And like Will comments, the list is pretty Google-centric. Hey, even though they are evil, they provide useful and simple to use services. I've gone over to the dark side.
Readers, what SHOULD be on this list?
Image source: http://www.marketingshift.com/2005/10/evil-empire-google-gaining-evil-ground.cfm