ESX Console Tab in VirtualCenter
This is a great little plug in by the folks who brought you Storage vMotion GUI. You can find the plug in @ http://akutz.wordpress.com/software/. Installation is done at the client side and no changes to the VMware environment are necessary making this a very low risk addition to environments.
Makes for a nice easy way to do console commands without ever leaving the comfort of the VI client. Be aware that most plug ins are not officially supported by VMware and are written by 3rd party developers. Due diligence and testing should be preformed before adding to production environments.
Interestingly, this functionality is already native in XenCenter.