I use added a "Remote Assistance" link in my custom actions, this allows us to use the built-in windows remote assitance to offer help to remote computers. Here is the syntax to use on vista and Windows 7 Hosts:
msra.exe /offerra {computer}
and for WIndows XP hosts (you will have to type the computer name):
"%ProgramFiles%\Internet Explorer\iexplore" hcp://CN=Microsoft%20Corporation,L=Redmond,S=Washington,C=US/Remote%20Assistance/Escalation/Unsolicited/Unsolicitedrcui.htm
Please note that you must run the correct command depending on what OS YOU are running, not the client.