I would have liked to show more than one example of a WPS client interface. But I was able to find only one among my current collection of wireless cards: D-Link's Client Manager. The reason appears to be that Atheros has done a better job than the other Wi-Fi chipmakers in implementing WPS on the client side. And since most of D-Link's wireless products are Atheros-based, they reap the benefits of Atheros' work.
I asked my Linksys contact whether there were any Linksys adapters that supported WPS and was told that, except for the WGA600N Gaming Adapter, there were none. Client support for WPS is supposedly coming soon, but given my previous experience with such reassurances (and not only from Linksys), I won't be holding my breath.
I could find no examples of WPS client support for Netgear, even in its latest WNDA3100 Dual-Band Wireless N USB Adapter. But, like many other manufacturers, WPS is supported in the companion WNDR3300 Dual-Band Wireless N router.
Figure 7 shows the D-Link client manager's main screen.
Figure 7: D-Link Client Manager with WPS support
Clicking the WPS button takes you to a PBC / PIN selection screen (Figure 8).
Figure 8: PBC / PIN selection
Selecting PIN takes you to a screen that provides the PIN that you enter into the Registrar, i.e. the wireless router or AP (Figure 9).
Figure 9: Client PIN screen
Selecting PBC takes you to the Figure 10 screen, where a click of the button starts the client's participation in a PBC session.
Figure 10: The magic PBC button
You'll see the Figure 11 screen while the PBC session is in progress. I found that this screen didn't stay up for long; most PBC sessions completed within 10-15 seconds!
Figure 11: PBC session in progress
Figure 12 shows a successfully completed WPS session.
Figure 12: PBC session completed
Again, there are too many screens for my taste. But at least WPS is supported!