The Keywurl Safari plugin allows you to associate any sort of keyword to a search query, significantly speeding up your web browsing.
The plugin is accessible and customizable from the Safari preferences menu.
All you have to do is choose a keyword and then paste in the url you want to associate to it. Keywurl can be set to not use unicode urls, which aren't supported by all web applications.
It can also automatically encode spaces, which comes in handy when these appear as '%20' or something similar.
Normally, typing a keyword in the url address bar, brings up a website associated with this keyword.
However the advantage with using Keywurl is that you can really set up your own keywords to a url. It's especially useful if you want to have quick access to a specific page or a search query that you normally wouldn't be able to type in, simply because the url would be much too long.
The only real drawback to the plugin is the installation process. You'll have to first install the SIMBL package then drag the bundle file to its plugins folder in Application Support.