Google Chrome has many useful extensions, like Firefox add-ons.
Official Google Chrome extensions
featured extensions
by Webappers
Ad block
Hola Unblocker - Proxy VPN service to watch Hulu or Pandora outside USA
Stylish (like Greasemonkey for Firefox)
Screenshot (or region) and annotate, save to png
Send from Gmail
YouTube downloader
This one doesn't work
Woopra realtime web analytics
Ibrii
Google tasks
Password manager
Web edit
Press F12 to edit, F2 to stop
Web developer
SEO
Similar Pages
https://chrome.google.com/extensions/detail/pjnfggphgdjblhfjaphkjhfpiiekbbej
Better Gmail
https://chrome.google.com/extensions/detail/gmfocnipihcoejdieiimhiecclokidea
Google Mail Checker
https://chrome.google.com/extensions/detail/mihcahmgecmbnbcchbopgniflfhgnkff
Google Translate
https://chrome.google.com/extensions/detail/aapbdbdomjkkjkaonfhkkikfgjllcleb
Resolution test
Speed Tracer
Email signatures with images
Needs "dev channel" version of Chrome
Webpage Screenshot
Full-page screenshot (scrolls for you), supports annotations and uploads to pict.com with public url
Another one (not as good)
https://chrome.google.com/extensions/detail/ckibcdccnfeookdmbahgiakhnjcddpkiPendule
Developer toolbox
BuiltWith
Shows what technologies the site you are viewing are using
iMacros
Snippy
Lorem ipsem generator
Docs PDF/PowerPoint viewer
FastestChrome and clickable links
Makes links clickable (works in Basecamp to-do lists)
Adds many other time-savers
Dictionary
Reminder
Slideshow
https://chrome.google.com/extensions/detail/gmfocnipihcoejdieiimhiecclokidea
Google Mail Checker
https://chrome.google.com/extensions/detail/mihcahmgecmbnbcchbopgniflfhgnkff
Google Translate
https://chrome.google.com/extensions/detail/aapbdbdomjkkjkaonfhkkikfgjllcleb
Aviary Screen Capture
https://chrome.google.com/extensions/detail/ncgcgghbabbopfcpgcjpfffdgnbadegf
EverNote Screen Clipper
https://chrome.google.com/extensions/detail/pioclpoplcdbaefihamjohnefbikjilc
https://chrome.google.com/extensions/detail/ncgcgghbabbopfcpgcjpfffdgnbadegf
EverNote Screen Clipper
https://chrome.google.com/extensions/detail/pioclpoplcdbaefihamjohnefbikjilc
Lists
Extensions for web developers