It's very easy to use: double-click the program icon in the system tray and select the area of the screen you want to capture. The picture is then automatically uploaded to the VVCap web server.
The image URL will appear in the menu bar and you can go to the system tray, click the icon, and select the URL for the last files uploaded. VVCap only shows the addresses of the last 10 images uploaded.
VVCap requires no registration and its use is both unlimited and free.