Google Toolbar button
This button redirects from the current page (http://domain.com/page.html) to a URL where a proxy domain is appended to the host (http://domain.com.proxy.u.edu/page.html). The proxy domain is set by the user at installation (default: ezproxy.library.arizona.edu)
The redirect preserves the path, query and bookmark of the original page, so that
http://domain.com/dir/page.html?q=query#bookmark
is redirected to
http://domain.com.proxy.u.edu/dir/page.html?q=query#bookmark
In order to access full texts of articles, I need to access the journal web site through the university library proxy. I simply got tired of typing in the 27 character long proxy domain in the address bar every time.
An alternative is to search through the proxy (e.g. using http://scholar.google.com.ezproxy.library.arizona.edu/), but I found that to be much slower at times (+ Google doesn't recognize your Google account this way).
If you have the Google Toolbar installed, you can add this button by clicking here.
As Google Toolbar v3 has {url} and {url.host} variables, but not {url.path}, this redirect could not be done without using a script of some kind. Currently, it is implemented in PHP at my personal web site. All the code does is a redirect using header("Location: $redirect_url") based on the current URL and the set ezproxy domain. No information is collected whatsoever. The source code is accessible here.