Speedo Errors

I am new to this forum but just bought a 2000 Tacoma. Seems like there is a wealth of info on this forum. I hope I can contribute a bit once I become more familiar with my truck. I do have one problem with my truck. After driving it for a bit I have noticed the speedo off. Has anyone had this problem and how did they fix it. Is it simple are hard to fix?? With chev's, the speedo can be calibrated through the computer. Is that possible with my Toyota?? thanks