The National Heart Lung Blood Institute at NIH has a downloadable BMI calculator that just requires height and weight and has all the classification, etc. based on the new national benchmarks. Unfortunately it is only for Palm right now. I am a Palm user who just ordered my Axim today and sent email to NHLBI to ask about availablity for PPC. They told me they are working on it and I am on an email list to be notified when it is available for download for PPC. Sounded like it would be the near future. Just an FYI. Checked out the other website mentionend in the other reply but the classifications don't fit with the new NHLBI guidelines.
check out
http://www.nhlbi.nih.gov and go to Obesity Education Initiative section.
Shank :)