Some members of BPF-Tampa Bay are involved with bringing Buddhist mediation to prisoners.
These sites provide an introduction.
Gainesville Zen Center Dharma Teacher K.C. Walpole's prison page: http://gatelessgate.org/prison/index.html
the Prison Dharma Network: http://www.prisondharmanetwork.org
the Prison Ashram Project: http://humankindness.org/project.html