I agree 500 meg a month i would say you use that amount in about 2 weeks or less so a plan upgarde would be good.

http://home.aapt.com.au/At_home/Int...iveNet5NTC.html

http://home.aapt.com.au/At_home/Int...veNet10NTC.html

These 2 plans would be fine, i am not sure if you are on adsl or adsl2+ at the moment but you may need a newer modem, stay off contract if you can and pay for the modem yourself if needed.

You will notice a world of difference with a new plan and 1 gig of ram.