It is possible to choose a user id for yourself which will be displayed in the statistics instead of the ip number. Just choose an id and write it in the box, then hit <return>. About the choice: Choose an id not already present in the list, otherwise your statistics will be added to the already existent id in the list.
In the standalone client, specify your user id as argument on the command line, as specfied in FAQ answer 7.
Drop me a mail if you want me to convert your old results (with ip number as id) to your newly choosen user id.