I'm always pushing the RDOS aspie quiz because I think that it's the most accurate one out there but I've just been referred to another one - which has similar questions and which uses the Baron-Cohen criteria.
So here's the URL (http://aq.server8.org/).
There's 50 questions and you should answer them fairly quickly so that first impressions count.
My score was 40.
To put this in perspective;
11-22 average (women=15, men=17)
23-31 above Average
32-50 very high (average Aspergers & HFA score is 35)