Linksys WAP11 has the ability to act as a wireless client

But only to other Linksys WAP11 devices. It (at least the v2.2 WAP11) will not work with anything else -- including other Linksys equipment.

I spent most of an evening last week trying to get my WAP11 into client mode with my (newly-purchased) Linksys WRT54G. It won't.

If you're planning on hooking an existing PC to a wireless network, look at the WET11 or WUSB11, or other manufacturers' equivalents.