I often use View Source in Firefox to view the page source after all Javascripts have run: CONTROL+A → Right-Click → View Selection Source.

As I work remotely and my two testing computers aren’t set up to do the VPN connection, I often use this technique to save out a copy of a page for viewing and debugging in IE7 and Safari.

Something to be aware of is that this generated source omits the page Doctype, which can mean funky rendering in IE7. Replacing the Doctype after pasting the generated code fixes this problem and creates one less diversion when developing cross-browser scripting and styling.

Update 11.08.2007: It also looks like source code viewed in this way is also converted to HTML markup, regardless or whether it was authored as XHTML or not.