Hi Aliard,
The biggest issues with showing your realtime position during a 100km will be
a) power - you will need more than one battery, or will need to re-charge.
b) robustness - if your phone is anything like mine it will freeze and need a reset every now and then. I also found if my phone could not get a GPRS signal the upload would sometimes lock up MyMotion.
I factored these in when designing MyMotion. The simplest way to show your position live is to send your location to an ftp site at a predefined interval. If your phone needs to be reset, just start MyMotion again and everything will continue. I also added power management to get the maximum life out of your battery. On the General preference there is a mode called "black box"; if you pick this MyMotion will allow the phone to sleep for 10 minutes then wake it up for long enough to get a signal and post it to the ftp site, then allow it to sleep again. Using this mode I could get about 10 hours of continuous usage out of one battery (whereas you would typically only get 1 or 2 otherwise).
With the ftp upload, here is what I recommend.
1. Make sure you are using the latest version of MyMotion
2. Use "Current Loc" as the Upload Type from the Preferences
3. Fill out your ftp info and select Auto Upload (yes, you need your own ftp site)
4. If the ftp site/username/password you supply is all OK, this should post a file called LL.deviceid.kmz to your ftp site each time interval or when you go Tools->File->Upload Now. The device ID is unique to your PDA, you can get it from Tools->Help->Register (press Cancel after)
5. You can pull down the kmz file via a PC script, program or something else of your creation, but what I found best was to use the network link feature with kml files. This allows you to link a PC based kml to a web based kmz via a URL and auto refresh at a specified interval. You can then just open this kml file up in Google Earth and it (and your PDA) will do the rest.. fingers crossed.
Here is a template network link kml file you can use (after changing the highlighted fields to your own values), just cut and paste it into a file and save it with the suffix kml, save it to your PC and open it up in GE (NOTE: you can also send it to other people if you want them to know where you are too!):
<kml xmlns="http://earth.google.com/kml/2.0">
<LookAt>
<longitude>150.00</longitude>
<latitude>-38.00</latitude>
<range>10000.0</range>
<tilt>45</tilt>
<heading>0.0</heading>
</LookAt>
<NetworkLink>
<description>Dynamic network link to name GPS phone</description>
<name>link.kml</name>
<link>
<href>http://yourwebaddress/LL.deviceid.kmz</href>
<refreshMode>onInterval</refreshMode>
<refreshInterval>400</refreshInterval>
</NetworkLink>
<styleUrl>root://styles#default+icon=0x307</styleUrl>
</kml>
