Sorry, but I'm a bit green. Does adding a large memory card do anything to benefit the web browsing? or is it just to save documents your working on, and saving photo/s etc? Does it enhance your ability to watch video clips, etc? I primarily use my machine to check web updates and email. Thanks.

A large memory card doesn't improve performance, except if you keep reading files from the card and you change from a very slow card to a normal card. A large card gives you lots of space for storing files though. Videos tend to be big, for example.

I also use my memory card to extend the virtual memory. It's my perception that it does help in loading web pages quicker aas wel as having more than one page open.

That's probably just perception, it can't speed up anything (except in very special cases). What the swap space gives you is more margin, i.e. you can load up more programs and data without running out of memory (which would result in a runtime failure or involuntary shutdown of one or more programs).