You can't get a free .com. There is no such thing as a free lunch..

You can always use a .tk or something if all you're looking for is easy access.
Another free

A bit like one of those free ipods sites (without referrals)

So you just sign up to some offers and they get some money from the makers of those sites and can pay for your domain, havnt tried it myself but its worth a look
Rofl, if you really want a freesteam clan then pay a couple of $ or ? for a .com domain. Its not expensive, and if i was really committed to a clan i'd fork out money for it, which i have done :)