Yes, but it depends whether the access point has a "client mode".
Many access points such as WAP11, WET11, DWL-900AP+, DWL-2100, DWL-G730AP, AP411W, etc have a client mode. All game adapters also can do this. The latest generation of "Pocket Router/access point/client" boxes will also do a client mode. Note that this "client mode" is NOT the same as "ad-hoc" peer-to-peer networking, which is similar, but not identical.
Just to make life complicated, there's also a difference between a client mode that will support exactly one client computah, and a variation that will support more than one computah (usually through a hub or switch connected to the access point in client mode). The data sheets usually don't specify the maximum number of clients that can be attached.