Thunderbird can export your contacts/address book, but I don't know whether your Android mail program can import them in that format or whether a lot of work will be required. When I look at Comcast's forums about how to import your Thunderbird contacts into webmail, they seem to suggest using a third party service called Plaxo. For example: http://forums.xfinity.com/t5/Email-Web-Browsing/Mozzilla-Thunderbird-Contacts-wont-import/td-p/2744779 Old timers may remember getting junk mail from Plaxo that a friend of theirs is now using the service; they may have bulk mailed everyone you imported. Hopefully they've stopped doing that by now, but if you decide to try it, check all the privacy settings carefully.