i have thought of starting a business and i am thinking to reg the following domains hiredesigner.org hiredesigner.biz hiredesigner.us how good are these domains ?
Be careful about posting names that aren't registered yet. Anyone can go and register them before you. I do agree with CrAzY-MaStER about going for a .com. I would go to either GoDaddy.com (use Smart Search) or NameBoy.com and see what is available with the word "Designer" in a .com.
if you are in the USA and developing the domain, hiredesigner.us is good. Not so good for domain flipping, but relatively short, easy to remember and appropriate for a personal domain.