What happens if you disrespect a judge?

Basically flip him off or refuse to refer to him as "your honor"?
Disrespecting a judge can result in being held in contempt of court [1, 2, 3, 4]. This means that the judge has found you to have disobeyed or been disrespectful of the court's authority [3]. The judge's strongest power to impose sanctions for acts that disrupt the court's normal process [3]. Normally, a judge can impose a fine or jail for someone found guilty of contempt of court [4].
You can be held in contempt of court for showing disrespect for the judge or disrupting the proceedings [3]. A contempt of court finding may result from a failure to obey a lawful order of the court, showing disrespect for the judge, disruption of the proceedings through poor behavior, or publication of material or non-disclosure of material, which in doing so is likely to jeopardize a fair trial [3]. A judge may impose a fine or jail time for someone found guilty of contempt of court, which makes contempt of court a process crime [3]. In the United States, judges generally have more extensive power to declare someone in contempt than judges in civil law systems [3].