The K-Desktop Environment. Fast and snappy, works well, looks good. I use it.  Many many utilities.  Easy to install in Fedora, just use yum group-install KDE

dimdim is a free and open-source web conferencing product similar to webex. It allows for presentations to be done over the web and is very useful for discussions and demonstrations. I have installed the alpha and beta versions of the server and used the alpha version quite a few times and it has worked very well (the beta version has some stability issues).

Unfortunately an incompatibility had crept in when using the presenter from within a VMware image when that image was running on a host using compiz. Not a terribly common setup perhaps, although visually very appealing. An easy fix to the problem is to revert the VMware image video driver back to the non-vmware version installed along with the vmware-tools.

Beryl

Related

Compiz - this is merging with Beryl.

Items marked with (nyt) indicate I have not yet tested it. I've heard
it's good (so it has made it on the list) but have not yet tested it
myself.

If you are ever looking for some amazing eye candy for Linux, try Beryl. On fedora 7 beryl installs easily by issuing a “yum install beryl*”. You can then use Beryl on your favourite window manager (such as kde) by selecting System -> Beryl Manager from your menus.