I'm about to buy an iMac. One question I have is is the 3.06GHz that much faster than the 2.8GHz? Is there a noticable difference? Also, what advantage would there be to buy the 24' monitor over the 20'? Lastly, I plan on doing internet, email, itunes, and creating slideshows and DVD's from my pictures and maybe creating my own webpage. Will the 2GB of memory and 320GB hard drive be enough to do these kind of tasks or should I upgrade to 4GB of memory and 500GB hard drive? Thanks.