While most popular web conferencing systems like WebEx, Microsoft Live Meeting, Centra, Genesys do offer screen sharing as part of their standard feature set, you do not need to spend the full price of these richly-featured enterprise conferencing systems when all you need is the ability to show your screen in a simple and reliable way.
By browsing through classified internal research statistics conducted by some of these large web conferencing providers, I have had confirmation that most online collaboration/conferencing meetings are generally made up of two to four people only, and leverage screen sharing, co-browsing and text-chat as their key features.
Given the above, and while large providers wake up to the idea of differentiating their feature set into multiple products and services, you really need not go into dumping hundreds of dollars a month to get a service that you will use only in limited part.
