How do I detach a process from Terminal, entirely?

I use Tilda (drop-down terminal) on Ubuntu as my "command central" - pretty much the way others might use GNOME Do, Quicksilver or Launchy.

However, I'm struggling with how to completely detach a process (e.g. Firefox) from the terminal it's been launched from - i.e. prevent that such a (non-)child process

• is terminated when closing the originating terminal
• "pollutes" the originating terminal via STDOUT/STDERR

For example, in order to start Vim in a "proper" terminal window, I have tried a simple script like the following:

exec gnome-terminal -e "vim $@"&> /dev/null &

However, that still causes pollution (also, passing a file name doesn't seem to work).