As a web developer, I use the 14 second rule. If the page can't load in 14 seconds using a 56K modem, it's too big and I re-work it. I make an exception for
some flash animations, but not those stupid splash screens.
On pages other than the home page, longer load times are acceptable, IF they tell me to expect a delay. I use a cable modem at home (10x the speed of modem), and at work I have 2 T-1's at my disposal
(hmm, where's the *evil grin smiley* when you need it). So if a page takes me any more than 5 seconds to load, it's too long!
I better get off my soapbox, before I get started on standards compliance!
(edit)Hey, my animation has a white background! I better fix it.(/edit)