beefbuckets

I have a 1996 supercharged gt and it recently has been idling at a very high rpm. The high idling has just occurred today and also for the first time. When the car is started it shoots all the way up to 2000rpm and stays there. Sometimes it drops to around 1600rpm or so but still remains high at idle and even while im driving it. The rpm's go up as i accelerate as its supposed to but they never go below 2000 while driving or at a stand still. Any ideas as to what is causing this to happen and is there anything i can do?