This page points out some ways you can use your web browser to get the most out of P4Web.
Using bookmarks
Right-clicking on links
Using the "Back" button
Resetting the page content limit
Displaying file content
Reducing P4Web's impact on the Perforce Server
Bookmarks can also be used to store any non-default settings you choose (current client, file display preferences, etc.) with Go To->Settings.
Since P4Web has no MIME information for files stored in Perforce, it sends file content to your browser without a MIME type header, and lets your browser decide what to do with it. Most browsers succesfully use the filename suffix and/or the first few bytes of the file content to determine how to open the file. Some browsers apparently can't make the leap, however; in these cases you'll either see garbage characters displayed in the browser, or an error message.