How to create a rpm from an installed package

To demonstrate this we will use the FTP package 

# rpm -qa | grep ftp

lftp-3.7.11-8.el5

tftp-server-0.49-2

ftp-0.17-38.el5

# rpm -e --repackage ftp-0.17-38.el5

# rpm -qa | grep ftp

lftp-3.7.11-8.el5

tftp-server-0.49-2

# ls /var/spool/repackage/

ftp-0.17-38.el5.x86_64.rpm

FTP package was uninstalled, repackaged, and then put in the /var/spool/repackage directory. The package can now be utilized as needed.