Have you looked into clinical trials? If you go to www.clinicaltrials.gov and use "precancerous mouth lesions" as your search term, you'll find a number that are recruiting, in various locations across the country. You have to scroll down into each study to find the locations -- a study may be sponsored by, say, M.D. Anderson, but patients might be recruited for that study through other medical centers as well as through MDA.

The National Institutes of Health, just outside Washington, DC, does clinical trials -- and depending on the trial, travel costs and/or accommodations could be covered. You could get in touch with LindaNIH, a research nurse at NIH who was recruiting OCFers for a dry-mouth study a few months back -- her contact info is in her profile.