I assumed that the ability to copy and paste text between your desktop and virtual machines had been removed entirely from the vSphere client. It turns out that it has just been disabled by default for security reasons and that it can be enabled per VM or per ESX host.
I found a need for this when setting up machines with little or no contact with the outside world, but that you want to make complicated configuration changes that you have previously documented.
Information on how to enable copy and paste in the vSphere client is available in VMware's KB article 1026437.
