When you visit a web page that has compatible user scripts on Userscripts.org, this extension will highlight the Greasemonkey icon in the status bar. Right click the Greasemonkey icon and choose the "X scripts available" item to see and install the scripts available for the current page.
Note that Greasefire uses a local index to look up scripts that apply to the page you are on -- it does not send any browsing data to a server. The index is updated periodically, see Add-ons -> Greasefire -> Preferences for details.
Please read the FAQ: http://code.google.com/p/greasefire/wiki/FAQ
Releases are available on the Firefox Add-ons site: https://addons.mozilla.org/en-US/firefox/addon/8352
Discussion forum on userscripts.org: http://userscripts.org/forums/5
These details are provided for information only. No information here is legal advice and should not be used as such.