How can I have commonly used applications running invisibly in the background from boot-up, so that when I need them they appear faster?

I am wondering if there is some way to quickstart applications, particularly OpenOffice.org and Mozilla Firefox, in the GNOME desktop. That is to say, when GNOME starts, these applications start up at log-in and run in the background, so when I launch them, I am essentially doing a "New Window" or "New Document" action which starts much faster. Don't confuse this with having the program open when I log-in, this is not the same.

I tried an application called OpenOffice.org-quickstart, but it didn't work at all. It put a menu on my panel, but none of the links for "Create new spreadsheet" worked, and OpenOffice.org still took forever to load when I ran it from the Applications menu. Also, when I quit GNOME, I received an error stating that OpenOffice.org-quickstart had not been exited properly.