ChrisControl is a Portable RDP + VNC Remote Control Tool. It can be used to test if a remote system is running Virtual Network Computing or Remote Desktop Protocol services via a given Host Name or IP address. If RDP or VNC services are found and the proper username and password are provided, it attempts to connect to the remote computer. If neither RDP or VNC services are detected, it will prompt the user to install VNC and attempt to connect.
NeoRouter is a Free Portable Remote Desktop Client and VPN Server. It can be used for Remote Desktop, Folder Sharing, Printer Sharing, Chat and more. The full package includes Server software with a Virtual Private Network (VPN) and will need to be installed on computers that you will be connecting to. You then use the portable client to connect to those machines.
Brynhildr formerly Zero Remote; is a free portable remote desktop program for Windows which includes both client and server in one package. This easy to use free remote desktop software allows you to remotely control another computer from a USB flash drive, on the go - no matter where you are.
TeamViewer Portable is a popular all in one (server and client) remote desktop program. This standalone RDP can be used for desktop remote control and desktop sharing. One key feature that differentiates Portable TeamViewer from other remote desktop utilities and tools is that it will also work behind a firewall or NAT proxy. Making it super easy to get your desktop up and shared quickly.