Top two recommend free remote desktop sharing tools
ShowMyPC
Show computer - http://download3.showmypc.com/ShowMyPC3005.exe
View computer - http://download3.showmypc.com/ShowMyPC3005.exe
Allows online collaboration, desktop sharing, and remote PC access. No registration required, no login and easy to use. Uses SSH to make remote connections.
Zolved
Show computer - http://www.zolved.com/Zolved%20Remote%20Control.exe
View computer - http://www.zolved.com/Zolved%20Remote%20Control%20Viewer.exe
Allows online collaboration, desktop sharing, and remote PC access. No registration required and no login. Uses UltraVNC to make remote connections.
Other free remote support tools
TeamViewer
Show computer - http://www.teamviewer.com/download/TeamViewer_Setup.exe
Viewer - http://www.teamviewer.com/download/TeamViewerQS.exe
Allows remote control of computers, screen sharing, file transfer, chat ability, and is secure. Have to install TeamViewer software. No registration required and no login.
LogMeIn
Remote desktop sharing. Access remote computers by installing a client software onto each machine. Works on servers and desktops. Free registration required.
Yuuguu
Remotely access your PC or MAC also. Works well through firewalls. Free registration required.
CrossLoop
CroosLoop easy to use, requires each party install the CrossLoop software onto their computers. Uses 128-bit encryption and allows for file-sharing.
SkyFex
SkyFex allows remote watching and remote control in real time. Does not require additional software installation works transparently through NAT and Firewalls. Only works on Microsoft Internet Explorer.
Dimdim
Remotely share your desktop features web conferencing, collaborate, share voice, video, slides and whiteboard. Free registration required.