The googleplusplus_default_circle userscript / extension for Google Plus adds a star next to each circle stream name. The star can be clicked to set or unset one circle stream as your default. When a default is set, going to the Stream view you automatically get redirected to your default stream.
Effectively, you can make one of your circles as the new everything you want to see by default based on one circle not all circles.
Works on Google Chrome 12 and Firefox 5 with Greasemonkey and should also work in Safari with the plugin NinjaKit .
Google Plus Search With Google
googleplusplus_search_with_google is a user script for Google Plus that toggles the built-in search input Find People with another option: Search Google Plus with the Google search engine using the site: filter.
Click TOGGLE SEARCH TYPE link to toggle between Find People and Search with Google.
GooglePlusPlus Hide Sidebars
The googleplusplus_hide_sidebars is a user script for Google Plus (aka Google+ aka G+) that adds a feature to hide/show left and right side bars, and makes the main content wider. This feature is sticky and will show either a Hide Sidebars link or Show Sidebars link.
Source and Read More here: Click here
Google Plus Blog.