wireless laptop to hdtv for meeting space

I have been asked by the manager of our office to look into the options for enabling visitors/employees to display presentations from their laptop on our 50" plasma hdtv.

I really want to go the wireless route so that we wont have any cabling running across the floor. I have been researching wireless VGA adapters and came across the Addlogix Wireless Echoview PC2TV. The only issue I have w/ this device is that is seems the software will need to be installed on every system before it can transmit the video signal.

I looking for something a user can just come into the conf room, plug in and be connected to transmit thier video signal to the TV wireless. Does anyone have any experience w/ anything like this? What do you recommend. I have a budget to stay under $300.

Thanks!