I'd like to know if the difference between 2 and 4 Gig of memory in the new iMac will be noticable when using programs like Photoshop or Illustrator? Here in Canada, it cost 750$ to upgrade from 2 to 4 gig, so, would i be winner if i just wait about 2 years and then buy some memory for upgrade? Also, i already have a PC here, and i will have to get a wireless router. So, my question is, if i configure a wireless network, will the connection will fail on my iMac if it is pu to sleep? Will, for example, a Messenger session still be active when it will be asleep? ANd also, does it worth the pain to buy Apple Airport Extreme, or could a normal router do the same thing for less?