For the media stuff, I llike to use Livna as they work closely with the "official" Fedora.us repository and the releases are "kinda" sanctioned. DO NOT MIX Livna repository with Freshrpm's as sometimes there are copatibility issues.
So add in the sources.list file:
rpm
http://rpm.livna.org/ fedora/1.90/i386 stable (for Fedora 2 test one)...if you are using Fedora 1 make sure you use the fedora 1 repository.
For Flash, I think that there is already a macromedia site in there for apt (assuming you got apt from fedora.us) however, I just install using the script installer provided directly from Macromedia.
for Mozilla, if you decide to updated or NOT use the provided Mozilla rpms...again, I just go to Mozilla and get the NON-RPM versions of whatever program you want and I usually install it in /usr/local. Be careful to make sure any previous versions are completely removed before doing manual software installations.
I use about 50 to 60% rpms and many times source and direct installations on my machine. Many people will tell you to either stay with rpms ONLY or something like that but if you are careful and keep a mental picture of what's installed and not (write it down), you can mix and match all kinds of things. THAT way, I don't always have to wait for the "official" versions...I can get the latest stuff myself.
For Mozilla, make sure that you get or find the GTK2 and XFT versions...NOT the stock versions.
I dumped Mozilla and use Firefox and Thunderbird for browsing and mail, respectively...both came without installers and are in /usr/local...you'll have to create your own links for your menu, desktop, and command-line if you like.