I registered myself, and when the payment receipt popped up in my email, I realized definitely didn't get to order the pins.
Then rightaway I decided to do my sisters' registrations and to get those pins!

It turns out that you get the pins by registering for them, as a separate event from the run. (You'll type all the name/addr info in for the pins, and again for the run itself)
Ie On
Wine-and-dine-half-marathon's main page, click on Commemorative Pins, then choose the 5k pins.
You should end up
here.
From that screen, choose either "Register Now" or "Click here to register now".
Both options take you to the
same waiver, then
Online registration screen, which is similar to the reg. screen for the RUN, but top of page states "2011 Disney Family Fun Run 5K - Commemorative Pin".....this is for the pin(s) ONLY! not pin + run.
SO!
Don't know if it matters what order you do it, or if you can go back a day or 2 later, but I did follow that process and reg'd for 2 pins, then went back to register for another event, and that time picked the run, not the pin.
And I did it again for sister #2.
It worked, here's a portion of the email receipt I got:
2011 Disney Family Fun Run 5K - Commemorative Pin
2011 Disney Family Fun Run 5K - Commemorative Pin
Sis 1 of 2's name was here $0.00
Would you like to purchase a 2011 Disney Family Fun Run 5K Commemorative Pin?
2011 Disney Family Fun Run 5K Commemorative Pin (2 @ $12.79 ea.) - $25.58
2011 Disney Family Fun Run 5K
Family Fun Run 5K
(Sis 1 of 2's name was here) $50.00
---(I deleted several lines)
2011 Disney Family Fun Run 5K
Family Fun Run 5K
(Sis 2 of 2's name was here) $50.00
---(I deleted several lines)
Processing Fee $9.16
Total $134.74
Hope this helps!