question is not clear. It sounds like you're looking for a way to allow your current users to let other users know of their presence on other social networks.
If that's correct then one way to do it would be to add some custom fields to their ACCOUNT SETTINGS -> PROFILE form to allow them to input what their other locations are then display those on their profile so the other users can click on it to reach them in the other locations.
That makes more sense now. You're talking about trying to get your marketplace settings working. Right now when you try to use the marketplace are you unable to install modules?
Do you get any errors?
If the marketplace is working then you dont need to enter any details there. Its a workaround method for if your system is unable to write to the modules and skins directory. You can fix that issue by allowing your system to write to those directories.
cool thanks. Just give me access when you know im there. No need to give your plumber a key to the house just in case he wants to fix something at 3am.