Port blocking is typically done through a firewall.
Many people utilize an alternate DNS server for their content-filtering needs, such as OpenDNS or Google DNS. These services give you the ability to block a large subset of domains regardless of ports. We provide the ability to set an alternate DNS server on our APs.
We've just recently been working on adding in content-filtering by way of Layer 7 packet inspection, but that's also regardless of ports. For instance, if someone were to be sharing BitTorrent files over port 80, we'd be able to detect it.