The following assumes you have the XChat package installed and are able to build source using scratchbox. The version of XChat I have installed is 2.6.4-2. I believe there are different versions available depending on what sites you have added to your application catalogue. I remember having problems with a different version.
You can install the Chicken library and the packedobjects shared object file as described here.
Get the thumbtribes source and build in scratchbox with the following command:
csc -s thumbtribes.scm xchat_init.c
You can then copy over the file thumbtribes.so to a suitable place on your Nokia. This will be the file you /load into XChat.
To add GPS capability you can do the following.