Pib is another useful package management tool. It's a Tcl/Tk-based browser which shows information on ports and their installation status.
The following is the Ports INDEX browser window. This screen shot shows the security/openssh-askpass port. We see it is installed because the green "install" keyword is lit. Ports that are not installed do not show "clean".
Pib is useful because one can quickly browse the ports tree, select a port, and read the description in the lower window. That window appears once the question mark icon is pressed. The window is persistent.
Pib also offers port searching capabilities. For example, one can search for a port and see its dependencies and the ports which depend upon it.
I'm waiting for this month's release of a new version of portsman, a ncurses-based package management tool.