<dd class="wp-caption-dd zemanta-img-attribution" style="font-size: 0.8em;">
Image via <a href="http://en.wikipedia.org/wiki/Image:Mobileme_Logo.png">Wikipedia</a>
</dd>
</dl>
If you find that there’s an address book card out there that isn’t syncing with MobileMe, your iPhone, or another Mac… check to see if there is an ampersand in the failing record anywhere.  Apparently once a card hits MobileMe, it doesn’t like the ampersand in the vcard and chokes on it.  If MobileMe chokes on it, all of your devices will be unable to find the new card.