We have many shredders that will shred a plastic ID card or proximity card.  Which one is best for you depends on your volumes.  Some of our shredders have a separate cutting head designed to accept only ID cards or CD's, which is fine if you only do one or two.  If you need to shred more, use the main throat opening.  We shred hundreds of plastic cards every week in our office, using the Intimus 120CC3. 

Any Intimus CC3 or CP4 model will shred id cards through the main feed opening.  One thing to remember is that if you're recycling your shredded paper, you don't want to mix plastic shreds with the paper.  Just use a temporary separate bag or receptacle.