Well, I can grab the tab off the browser window, then enable 'always on top'. But yep, that's more than one click, so I guess if someone does this all the time then it makes sense for them to automate it.
Yeah, I almost mentioned that I'm using gnome on linux but then I thought that this must be a ubiquitous feature. Now I'm surprised and have to look up if "always on top" was there in windows XP (the last version I've used) or not. :)
Also, don't forget you have Smart Positioning :) That feature is pretty powerful IMO.