This company refits them as deer stands:
Deer hunters looking for a cheap, weather-resistant stand might want to consider their local sanitation company.
Melinda Rodrigue, owner of McDonald Sanitation Services in Thibodaux, has been selling stripped-down and sanitized portable toilets for this purpose for the last three years.
Via Field Notes, which asks, "Would you hunt out of one?" (The toilets don't work anymore, FYI.)