OpenVPN is a full-featured SSL VPN solution which can accomodate a wide range of configurations, including remote access, site-to-site VPNs, WiFi security, and enterprise-scale remote access solutions with load balancing, failover, and fine-grained access-controls.
OpenVPN is normally run in a console window, which can be a little annoying to have lying on the taskbar all the time. OpenVPN GUI lets you run OpenVPN without this console window. Instead you get an icon in the notification area (the area on the right side of the taskbar) from which you can control OpenVPN to start/stop your VPN tunnels, view the log, change your password and other useful things.
OpenVPN GUI is an Open Source project and is licensed under the GPL.
Features in OpenVPN GUI:
Shows an icon in the notification area from which you control OpenVPN.
Handles multiple simultaneous connections.
Hides the OpenVPN console window.
Log file viewer.
Edit Config (with a texteditor).
Start/Stop/Restart the OpenVPN Service (see install.txt for enabling this command).
Dialog for entering the private key password.
Dialog for entering username/password authentication credentials
Change password used to protect the private key (Both PEM and PKCS #12 files).
Configure Proxy Settings from the GUI.
Use Internet Explorer Proxy Settings (only if manually configured in IE).
Execute a batch file before/after connecting and before disconnecting.
Cmd-line option to autostart a connection at startup (--connect).
Cmd-line options to override registry settings.
Shows connection info in the icon tool tip box.
System Requirements:
OpenVPN GUI is written in pure Win32 C code, so it does not require any run-time librarys to work. It is just a single exe-file (about 100KB).
OpenVPN 1.5 or higher. (Might work with earlier versions, but this is not tested)
OpenVPN 2.0-beta6 or higher to support multiple simultaneous connections.
OpenVPN 2.0-beta11 or
EU
OpenVPN Connect Windows packages
Mathias Sundman 
Comments and Reviews
Easy to use and configure, I did not create my setup *.OVPN, but I used the services of VPNBook.com, so the only things I've done is to creates a file that contains my credentials and I linked them with configurations.
After, the interface is very simple, sometimes the network bit buge but it is very rare (for me anyway).
Almost all VPN servers are paid, and free versions are not very useful, so OpenVPN-Gui is perfect to login to sites limited by country, or by using a Public Hotspot (railway stations, Hotels...) for Peer-to-Peer.
In addition there are full of Guides and Wiki on the web, so there is always help somewhere ;)
You can download the latest version here: https://openvpn.net/index.php/open-source/downloads.html (At me in "About" I have version 5, but it seems to me that it is the 2.3.4 on openvpn.se they have the maximum 2.1_beta7 version)