On Fedora Core 4, the command history search function is not bind to any key. Therefore if you want to find a command you typed in, you will have to go through them all.
A solution is to create a binding for this search function. Edit the file /etc/inputrc and add the following 2 lines :
"\C-f": history-search-backward
"\C-g": history-search-forward
Logout and log in again and Voila !
Type the beginning of the command you want to find and press CTRL-f ou CRTL-g.