Requested feature overview description.

require 'digest/md5'

profileImage = Null

#Greater than 0, aka: avatar is a post, and enableAvatars is equal to 1(Enable post avatars)
if userFromID(id).userSettings[:avatar] > 0 and currentUser.userSettings[:enableAvatars] == 1 then
    profileImage = e621.getThumbnailURL(userSettings[:avatar])

    maxRating = userFromID(id).userSettings[:profileAvatarMaxRating]
    
    #Do rating handling here

    write("<a href=\"${userSettings[:avatar]}\"><img src=\"${profileImage}\"/></a>")

#Avatar is equal to -1, aka: gravatar, and enableAvatar is equal to 2(Enable gravatar avatars)
elsif userFromID(id).userSettings[:avatar] == -1 and currentUser.userSettings[:enableAvatars] == 2 then
    email_address = params[:email].downcase
    hash = Digest::MD5.hexdigest(userSettings[:email].downcase)
    
    maxRating = userFromID(id).userSettings[:profileAvatarMaxRating]

    #Convert e621 ratings to Gravatar ratings: G, PG, R, X
    if maxRating == "S" then
        maxRating = "g"
    elif maxRating == "Q" then
        maxRating = "pg"
    elif maxRating == "E" then
        maxRating = "x"
    end
    
    profileImage = "https://www.gravatar.com/avatar/#{hash}?s=150&rating=#{maxRating}"

    write("<img src=\"${profileImage}\"/>")
end

Why would it be useful?
People have been wanting to use custom avatars but are often deleted because of quality control. Gravatar solves this in multiple ways:
1) No need to add complicated upload mechanism to e621
2) Gravatar lets people upload what they want

The code(although probably improperly formatted) solves multiple issues too:
1) Users can choose to not see gravatar avatars and still see regular posts as avatar avatars
2) Users can choose only to see avatars of specific ratings
3) Bonus: users can also choose to see avatars of specific ratings on e621 now too

What part(s) of the site page(s) are affected?

• User profiles
• User posts
• User avatar

+1 this'd actually be a really good idea. Though the option to use posts as avatars should still be available.

JAKXXX3 said:
+1 this'd actually be a really good idea. Though the option to use posts as avatars should still be available.

It doesn't replace posts as avatars, it uses a special modification to the posts as avatar, so removing that would break the addition of this.
Basically: setting -1 as the avatar will cause it to use gravatar instead.

Chaser said:
It doesn't replace posts as avatars, it uses a special modification to the posts as avatar, so removing that would break the addition of this.
Basically: setting -1 as the avatar will cause it to use gravatar instead.

Isn't that rather unintuitive? Wouldn't a multiple choice option be more user-friendly?

For example, under the 'avatar' heading, there'd be two text boxes with a multiple choice bubble next to them. The user will select the option they want to use, and the other option will be greyed out. Only the post/gravatar referenced in the selected text box would be used as an avatar.

JAKXXX3 said:
Isn't that rather unintuitive? Wouldn't a multiple choice option be more user-friendly?

For example, under the 'avatar' heading, there'd be two text boxes with a multiple choice bubble next to them. The user will select the option they want to use, and the other option will be greyed out. Only the post/gravatar referenced in the selected text box would be used as an avatar.

You could have a checkbox labelled "Use gravatar" which treats the avatar id as if it were -1 when checked.

BlueDingo said:
You could have a checkbox labelled "Use gravatar" which treats the avatar id as if it were -1 when checked.

Yeah, something like that would be better. Otherwise a ton of new users would clog up the forums asking how to enable gravatar avatars.

I'd rather not have 3rd party services attached to our page, at all.

Some random forum for discussing about random stuff and thangs, why not. Site which contains explicit furry material, where many would rather not get connected to their other online identities, let alone real one?

I know gravatar hashes users email address and uses that, but if user is using same avatar elsewhere, it's easy to connect.

Was also thinking about the issue that would rise from this: user wanting avatar because of this site specifically, which would then require them to register a new account on completely differend site. Of course this is pretty small issue, but I do hate when sites make you to register, just so you have to register on third party site again.

I can see a lot of drama in the takedown section if someone sees their OC used in someones Avatar (seriously why do people do that). I don't see an easy way for image owners to file takedowns on Gravatar so that's sure to cause confusion and piss off people more.

More work site admins doesn't sound good, as they would likely need to disable users Avatar capabilities when requested in takedowns.

-1