Speed up file transfer between home network

Hello,

I have a wireless network at home, I have my sony vaio laptop connected
directly to my hub. I have then my G4 Powerbook wireless. I remember a
few months ago, whenever i used AIM or any other source to transfer huge
files e.x600MB it'll take like 5minutes Now it takes like 30mins. I dont
know what happened why it got slow like this.
Any Help anyone?

I'm using a Wireless Belkin Rounter then i have an 8 port Hub hook up to
it..
so it goes... cable modem--->Belkin wireless Router --->8 port hub