The .lmx file format is a XML landmark format used by Nokia Maps. It can be sent via e-mail, MMS, etc., and lets you add metadata to GPS POIs.
<?xml version="1.0" encoding="UTF-8"?>
<lm:lmx xmlns:lm="http://www.nokia.com/schemas/location/landmarks/1/0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.nokia.com/schemas/location/landmarks/1/0/lmx.xsd">
<lm:landmarkCollection>
<lm:landmark>
<lm:name>A Vida Portuguesa</lm:name>
<lm:description>A local shop for local people.</lm:description>
<lm:coordinates>
<lm:latitude>38.7100765295327</lm:latitude>
<lm:longitude>-9.14113696664572</lm:longitude>
</lm:coordinates>
<lm:addressInfo>
<lm:city>Lisboa</lm:city>
<lm:country>Portugal</lm:country>
<lm:street>Rua Anchieta 11</lm:street>
<lm:postalCode>1200</lm:postalCode>
<lm:state></lm:state>
<lm:phoneNumber></lm:phoneNumber>
</lm:addressInfo>
</lm:landmark>
</lm:landmarkCollection>
</lm:lmx>