Is it an MODL 175 application, or non-MODL? That will make a difference as to how fast it's processed. MODL just means the occupations are in demand, hence processed faster.
It could take anywhere from 6-12 months for low risk countries. You can check out the British Expats site to see how long its' taking for applications. There's always lots of discussion about that.
http://britishexpats.com/forum/forumdisplay.php?f=32
You can also look at the British Expats Timeline site, where people put their own details in and it gives you a bit of reference for your own application.
http://www.beupdate.co.uk/indexvisa.php
There's also another timeline site that where people put information on as well.
http://www.austimeline.com/
The site seems to be down at the moment though, so maybe it'll be up later. It's not a government site so it relies on people to put their own information in.
There is no way to know where you're actually sitting though. So there's no point in bugging them trying to find out how much longer. I tried many times myself but all they can tell you is what types of applications they are processing at the moment. So they'll tell you what month they are up to with your types of applications. Not much else to find out that way. I found the timeline site with British Expats great because you could see who is getting visas and when they applied.
Don't worry though, not too much longer. We applied in 2006 and it took 6-7 months in total. We also send in our medicals and police checks at about the 5 months mark so that helped speed things up a bit. Ours was an MODL application and it was paper based.