Sometimes little things can make a huge difference in usability -- the Metasploit Framework Console is a great interface for getting things done quickly, but so far, has been missing the capability to save command and module output to a file. We have a lot of small hacks that makes this possible for certain commands, such as the "-o" parameter to db_hosts and friends, but this didn't solve the issue of module output or general console logs.
As of revision r13028 the console now supports the spool command (similar to database consoles everywhere). This command accepts one parameter, the name of an output file. Once set, this will cause all console output to be shown on the screen and written to the file. Calling the spool command with the parameter "off" will disable the spool. Even better, this command opens the destination file in append-only mode, so you can add the following line to your ~/.msf3/msfconsole.rc to automatically log all of your output for the rest of time:
Thanks to oorang3 on freenode for the suggestion. To access the new command, use the msfupdate command on Linux (or just "svn update") or the Metasploit Update link on Windows.
If you are running a version of the Metaspoit Framework that used one of the binary installers prior to 3.7.2, we strongly recommend upgrading to take advantage of the improved auto-update capabilities and dependency fixes in that release.