Update:The Shirtless Friendly Directory has moved to Wikia! Go there, and you can make your contributions by editing the wiki directly!
This site provides a public resource for those who would like to find a gym, recreation facility, etc that is shirtless-friendly. Anyone is free to submit information for inclusion in the directory. Submissions can be emailed to firstname.lastname@example.org. Please explain how you know the facility is shirtless-friendly (is it official policy, or have you visited the facility shirtless?), the degree of openness to shirtlessness (is shirtlessness allowed in some areas but not others? what percentage of other patrons are shirtless?), and when you verified this (were you there last week, or was it four years ago before you moved?). Businesses are also welcome to submit themselves for inclusion in the directory as well.
It has been pointed out that Crossfit gyms are almost universally excepting of shirtlessness. They focus on working hard and tend not to have lame rules restricting apparel. They are independently owned, however, and each has their own policies.