2X Client portable, now Parallels Desktop is a remote desktop client that can be used to connect to your remote desktop servers. The portable 2X-Client Parallels Client is available for download on the authors site.
NeoRouter is a free portable remote desktop client and VPN solution that allows users to securely connect to remote computers and private networks over the internet. It supports remote desktop access, folder sharing, printer sharing, chat, and more.
The full Neo Router package includes VPN server software that must be installed on the computers you intend to connect to. Once the server is set up, the portable NeoRouter RDP client can be run from a USB flash drive to securely connect to those machines from anywhere in the world where you have internet access.
Kidsnapper is a Free Portable Remote Screen Capture software that can be used to send screenshots (snapshots) to a web browser running on a remote computer. It is good for showing things to people remotely (coworkers or customers at a remote location). The utility might also be used to monitor the activity via remote screenshots of children on a remote computer (hence the name).
Brynhildr (formerly Zero Remote) is a free portable remote desktop program for Windows that includes both client and server components in a single package. This lightweight remote desktop software allows users to securely control another computer from a USB flash drive, on the go, without installation.