I know that hosts.allow and host.deny only affect things that are tcpwrappered, but what does this mean in practice? It seems that most people use hosts.allow to handle ssh and nfs blocking, but what other services are typically handled there? And what services AREN'T typically handled there?

Edit: ok, I realize I did a terrible job of explaining what I was after. No, I'm not interested in knowing if a particular service can be handled by hosts.allow, I want to know if a service will be handled. For example, if I do an lsof -i, I get a nice list of things that are listening for connections to my box. I want to know which ones will be affected if I go stick an entry into hosts.allow (well, I really want to know which ones won't be affected).