I think the probation costs about $50 to sign up - and you have to admit guilt. If you mess up in that time period, you get to pay your original fine, the new one, and you're still out the $50. But this can be a way to avoid having to pay higher insurance...

If you show up, give an honest account, the judge will almost always drop the fine down to the administration costs (something like $40) if he's not in a nasty mood...

I've heard stories about people challenging the offense and requesting lazer/radar gun calibration records and/or for the officer to be present. Apparenty, if you requested documents and/or the officer to testify, and something slips through the cracks (they don't send the records or the officer doesn't show), they have to throw out the case. This may be BS, but that's what i've heard.