In previous version of vSphere/ESX you could disable copy/paste when using the vSphere client by adding to lines to the advanced options of the VM:
Note tho that with 4.1 copy/paste is disabled by default (see here) so if you want to enable that functionality you’ll have to use
isolation.tools.copy.disable | false
isolation.tools.paste.disable | false
For further isolation methods check out the Hardening Guide from VMware.
One of the other nifty tricks is
Which will keep users who have client-access to the VM from being able to connect or detatch CDROMs, NICs, floppies and USB devices.