QUOTE(BrainDrain @ Nov 5 2005, 12:48)

So, does it actually save pages, e.g. forums, or live auction sites and then reload them from cache without telling you or does it only save pages you tell it to?
Your internet traffic is being redirected through Google's servers so what you see is most likely cached. The big issue is that sometime's people's passwords are cached as well and I've learned that although they've fixed a big part of this problem, some poorly built websites can still get cached incorrectly. Google claims this is the webmaster's own fault though.
Another problem is that because your traffic is routed through Google's servers, Google can see what websites you visit and your personal information is going through their servers too. I wouldn't trust it.