Run vSphere client 4.1 in a snap. No install, just download the EXE and double-click. Place the ThinApped vSphere client on any network share and it will automatically stream to any Windows PC with no installation, agents, drivers, or specialized servers required. Carry ThinApped vSphere client and your customization on USB stick and now your vSphere client is available on the GO!
http://labs.vmware.com/flings/thinapp-vpshere
btw: vSphere Client 4.1.0 Build 260247