You can get Webex MeetMeNow: free [here]
You can also try GoToMeeting:(a webex alternative) free [here]
For a truly free webex alternative there are some open source options, which seriously lack the features of their commercial competitors but which can easily be developed. For example, Dim Dim can be used to host meetings. There is also CrossLoop which can be used for remote desktop sharing.
Andrew - Mikogo said
Mikogo is also a great way to make the most from free online meetings. Mikogo is a freeware tool and allows you to share your screen in real time with up to 10 meeting participants. Remote keyboard and mouse control means it functions as a remote support tool as well.
Check it out at http://www.mikogo.com
Cheers,
Andrew
The Mikogo Team