Dr. Rey -- Big in Prison
"Dr. 90210" has a ton of fans ... at correctional facilities all over the country.
![0-wdswtryr](https://imagez.tmz.com/image/b0/16by9/2011/12/18/b00115137e01507b8a2331b17be35406_md.jpg)
Yesterday in Beverly Hills, the good doc Robert Rey read us a letter from incarcerated supporter Rod -- who specifically asked for an 8x10in photo ... which he'll probably hang in his 8x10ft cell.