I would not like to be bitten by them – They can give you a nasty bite and like many insect bites you can have an analectic reaction to the bite. I would not give one of these guys a chance to bite. DO NOT play with these guys as they are very aggressive. And they tend to stay in their web (Hide in the funnel when startled).
If you get bitten – I suggest ice on bite. If you have trouble breathing or nausea go straight to the emergency department at the nearest hospital. If an elderly or young person gets bitten by ANY spider – seek medical treatment.
http://en.wikipedia.org/wiki/Black_house_spider
http://usq.edu.au/spider/find/spiders/504.htm
http://www.termite.com.au/spider-identification.html
Omg_a_geco – I doubt you were bitten by a black window spider (Black house spider) as they are not normally seen walking across flat areas (Paths). I would suggest it was a wolf spider. They can pack a very painful bite – do not have a web – and tend to be walking on flat surfaces. When threatened they will lift their fangs up and bite – where as a Black House Spider tends to be more run away.
http://www.csiro.au/resources/ps1rt.html
kakariki – The only Australian spider that is considered deadly is the Sydney Funnel Web. All others can pack painful bites but are generally not fatal. If you leave spiders alone they will leave you alone.