I've done my time! I was called up and sat through the training, waiting to have my number called out so I could act as a juror. It went on for a month, but my number was never called. All in all, it was an interesting and easy way to earn some money, without having to do terribly much. I'm happily front up again if my name was picked.
I was called up once - not long after I became an Aussie citizen and therefore put on the electoral roll. I was too busy at work so was excused. I have no desire to do this and I don't believe it should be compulsory. Apart from the length of time a trial may take, it could be stressful for some people who don't want to have that responsibility i.e. knowing your decision (hopefully the right one) could greatly influence the outcome of someone's life. There seems to be plenty of people out there who really want the opportunity to serve as a juror.
I was called several times but didn't want to serve. Gave my excuse the first time and the clerk said, fine, explain to the magistrate and you should be okay. Waited for jours to be called only to be told just before lunch break that we wouldn't be required so they got out of having to provide lunch for us. Second time, discharged again but on the third time explained my problem to the clerk who said she'd make sure I wasn't called again, and haven't been.