If you use Twitter you can now put your username in your profile. By doing this, it will appear alongside all of your posts as a link directly to your Twitter page, like the online game IDs we have already (see mine on the left for an example).
If you want to add yours, go here: http://www.igta5.com...e&module=usercp
It'll also appear on the registration page for any new members, though it's entirely optional.