View source for Firefox/Feature Brainstorming:Tab freeze and low memory consumption

When multiple tabs are open, often happens that most of them opened "for future reference". Some extensions (like SaveMemory at http://www.savememoryfirefox.com/welcome/) try to do something with it - but from extensions you can only reload page when "unpausing" it. Reloading is not always acceptable - for example, if page have some JavaScript-jenerated content, it wil not be restored. Often user don't want to reload page becuse it's content may change (for example, constantly-updating news feed or statuses screen on Facebook).

It would be useful to add possibility to serialize full page to disk in it's current state - DOM tree, javascripts, event subscriptions etc, and ways to restore it from this serialized representation.

With this functionality memory usage of Firefox can be radically (many times) reduced by swapping out background tabs.

Some pages (that do not have timer subscriptions and Ajax/websocket connections) can be swapped off from the memory without any ill effects at any time. Others can be swapped on user request (for example, if page uses JS to play animation). Some, of cource, can not be swapped, because background activity is really useful (like shared Google Doc updating).

Other areas where this feature can be useful:
- "View source" screen
- Session save\restore - it will be more comlete than now.
- "Save page" with guarantee that ALL content is saved (for example, now news in Google Reader will not be saved withoud extensions).