ubquity for firefox is an amazing idea
firefox being the open platform that it is has been working on something called ubiquity. this is a plug-in for mozilla that allow the user to activate the command prompt and pull data from a number of places quickly and easily. it also allows the grabbing of data for insertion into one place (e.g. email or calendar).
i read about it a couple of days ago and then heard about it again yesterday on the buzz out loud podcast which drove me to a google search. tom merritt from BOL said it best - you have to see it to best understand it. check it out! this is one of the best implementations i have seen in a while and believe this could be a way that we all interact with the web in the coming years.