I do most of my website development work in Firefox, due to the availability of extensions such as Firebug, YSlow, and Tamper. Sometimes, I want to check a page in another browser so I can log in as a different user. This simple Applescript, combined with Quicksilver, allow me to easily open the current Firefox page in Safari:
tell application "Minefield" to set theURL to «class curl» of window 1
tell application "Safari"
open location theURL