'Google Keep' is Google's most recent foray into the digital notetaking universe (1). Available at https://drive.google.com/keep/ or via an Android app (2), Keep allows you to quickly save your thoughts in text, voice, and photo form for future reference.
As described on AndroidCentral (3), a third-party developer created a very convenient Chrome extension that allows you to launch Google Keep in a pop-up, panel, or new window from a launcher in the Chrome extension bar (4):
Unfortunately, Google recently removed this extension from the Chrome App Store, probably because it was named 'Google Keep Extension' and Google is working on its own solution. If you'd still like to give it a shot, click here to download my archived copy of the extension. Then, navigate to chrome://extensions and drag and drop the .crx file into the browser window to install it (5).
By default, this extension just opens Keep in a new tab and isn't much different from a bookmark. To change its behavior, right-click on the extension launcher and select 'Options'; from here, you can configure whether Keep opens in a Panel, a Pop-Up, or a New Tab. To get the Panel version working, you must navigate to chrome://flags, 'Enable Panels', and restart Chrome.
Some of you might remember Google Sketchpad (6) or the awesomeness that was Google Notebook (7). Here's hoping that the mobile component was the missing piece of the puzzle, and Google Keep will be more successful than its predecessors!
EDIT
This explains it: Google's official Keep for Chrome app is now available (8). Curiously, it doesn't have a Panel option or the right-click context menu options that the unofficial app did. For now, I'm keeping both versions installed.
(1) http://googleblog.blogspot.co.uk/2013/03/google-keepsave-whats-on-your-mind.html
(2) https://play.google.com/store/apps/details?id=com.google.android.keep
(3) http://www.androidcentral.com/expand-your-google-keep-use-chrome-extension
(4) https://chrome.google.com/webstore/detail/google-keep-extension/jccocffecajimkdjgfpjhlpiimcnadhb
(5) http://www.howtogeek.com/120743/how-to-install-extensions-from-outside-the-chrome-web-store/
(6) http://www.omgchrome.com/google-stopping-development-of-scratchpad-web-app/
(7) http://www.google.com/googlenotebook/faq.html\
(8) https://chrome.google.com/webstore/detail/google-keep/hmjkmjkepdijhoojdojkdfohbdgmmhki/