Just wanted to let potential switchers know of my 'minor' triumph on the weekend.
I only received my 2 new iMacs on Friday. On Saturday I plugged my ADSL modem into an Airport Express, installed a D-Link wireless card into a Pentium 4 - 2.4 ghz box - spent about 20 minutes making new locations on the iMacs - switched on the Airport and WOW. We were all connected. Spent about another 15 minutes 'fiddling' and all 3 computers had Internet access with excellent speed, all computers could print to 2 different shared printers and all 3 computers could 'see' each others shared folders.
I was staggered at how successful I was in such a small amount of time. I hadn't touched a Mac for over 15 years.

I can NEVER go back.