FURL

Usage: FURL <nick> <URL> <Frame>

This command will force a user's browser to open and view an URL. This will only work on java users.

Example:
/furl John http://www.webmaster.com/update.htm
/furl John http://www.webmaster.com/update.htm frame2

This can also be disorienting, and it is best to warn users of what you are doing. However, it can be useful for a presentation or to send users to a help site.