HamQTH is a yet another hamradio callbook.
You can try XML callbook search, for example, as in a following manner:
% wget "http://www.hamqth.com/xml.php?id=your_session_ID&callsign=jh1ood&prg=myprogam" % cat xml.php_something.. <?xml version="1.0"?> <HamQTH version="2.0" xmlns="http://www.hamqth.com"> <search> <callsign>jh1ood</callsign> <nick>Mike</nick> <qth>Tokyo</qth> <country>Japan</country> <adif>339</adif> <itu>45</itu> <cq>25</cq> <grid>PM95sp</grid> <adr_city>Tokyo</adr_city> <adr_country>Japan</adr_country> <adr_adif>339</adr_adif> <lotw>Y</lotw> <qsl>N</qsl> <eqsl>Y</eqsl> <email>jh1ood_at_gmail.com</email> <latitude>35.6378</latitude> <longitude>139.5042</longitude> <continent>AS</continent> <utc_offset>-9</utc_offset> <picture>http://www.hamqth.com/userfiles/j/jh/jh1ood/_profile/blueracer2.jpg</picture> <lookups>26</lookups> <registered>Y</registered> </search> </HamQTH>