Hello, as always i suggest XML::Twig

I'm not an XML expert so i confess i found some probelm in your data example, german char included..
I put the modified data in a file. You can see the content after the __END__ token in the script:

use strict;
use warnings;
use XML::Twig;

my $t= XML::Twig->new( pretty_print => 'indented',
                    twig_handlers => {

                          'node'=>sub{print $_[1]->att('id'),', ',$_[1
+]->att('lat'),', ',$_[1]->att('lon'),', ' ;

                                      foreach my $tag ( $_[1]->childre
+n ){
                                              print $tag->att('v').", 
+";
                                      }
                                      print "\n";
                          },

                    }
);

print "#ID, LAT, LON, CITY, HOUSNUMBER, POSTCODE, STREET, NAME, PHONE,
+ SHOP, SOURCE, WEBSITE, WHEELCHAIR\n";
$t->parsefile('xml-001.xml');

__END__
<?xml version="1.0" encoding="UTF-8"?>
<root>
<node id="297467" lat="49.5014" lon="8.1465">
    <tag k="addr:city" v="Stuttgart"/>
    <tag k="addr:housenumber" v="23"/>
    <tag k="addr:postcode" v="69115"/>
    <tag k="addr:street" v="Sofienstrae"/>
    <tag k="name" v="ARLT"/>
    <tag k="phone" v="+49 6221 20229"/>
    <tag k="shop" v="computer"/>
    <tag k="source" v="survey"/>
    <tag k="website" v="http://www.arlt.com"/>
    <tag k="wheelchair" v="yes"/>
</node>
<node id="305144906" lat="49.40012" lon="8.6929652">
<tag k="addr:city" v="Mainz"/>
<tag k="addr:country" v="DE"/>
<tag k="addr:housenumber" v="13-15"/>
<tag k="addr:postcode" v="69115"/>
<tag k="addr:state" v="Baden-WUrttemberg"/>
<tag k="addr:street" v="Rohrbacher StraSSe"/>
<tag k="name" v="Heidel-bike"/>
<tag k="opening_hours" v="Tu-Fr 10:00-18:30; Sa 10:00-14:00"/>
<tag k="shop" v="bicycle"/>
<tag k="website" v="http://www.heidelbike.de/"/>
<tag k="wheelchair" v="yes"/>
</node>
</root>

__OUTPUT__
#ID, LAT, LON, CITY, HOUSNUMBER, POSTCODE, STREET, NAME, PHONE, SHOP, 
+SOURCE, WEBSITE, WHEELCHAIR
297467, 49.5014, 8.1465, Stuttgart, 23, 69115, Sofienstrae, ARLT, +49 
+6221 20229, computer, survey, http://www.arlt.com,
 yes,
305144906, 49.40012, 8.6929652, Mainz, DE, 13-15, 69115, Baden-WUrttem
+berg, Rohrbacher StraSSe, Heidel-bike, Tu-Fr 10:00
-18:30; Sa 10:00-14:00, bicycle, http://www.heidelbike.de/, yes,
[download]

..and an handful of links from my homenode:
XML "If you need to deal with XML, first, we’re very sorry." b d foy http://www.effectiveperlprogramming.com/2011/07/rewrite-xml-with-xmltwig/ and http://www.effectiveperlprogramming.com/2010/03/process-xml-data-with-xmltwig/ and http://it-is-etc.blogspot.it/2012/07/perl-how-to-manipulate-xml-files-using.html and http://perlmeme.org/tutorials/parsing_xml.html speed comparison http://www.robinclarke.net/archives/xml-parsing-with-perl mirod schratchpad and Re: Another simple XML Twig question and http://www.xml.com/pub/a/2001/03/21/xmltwig.html ambrus's Do not reinvent the wheel: real-world example using XML::Twig and also http://perl-xml.sourceforge.net/faq/ and choroba about XML

HtH
L*