If you’ve been watching the stock markets and finiancial news today, you will have noticed that LinkedIn had a very good day. Professional social-networking website LinkedIn went public today, and while they had initally valued their stock at $45 per share, by the end of the day it closed at $94 per share, more than double what was expected. This gives the company nearly a 9 billion dollar value.

Some have speculated that LinkedIn is overvalued, but all recent trends have indicated that startups are once again hot commodities. Facebook and Twitter have also been valued in the billions of dollars (though they do not currently trade publicly).

So what does this mean to you? All of these businesses are growing rapidly and finding huge success, and all of them were started solely as online businesses. All of them were founded by entrepreneurs with an idea, a domain name, and a website. There’s nothing stopping you from doing the same thing. Embrace your entrepreneurial spirit and register the domain name  for an idea that you’ve been considering. Or if you’re like many of us, you may have purchased domain names for various ideas but never followed through on creating a website and promoting the business idea. It’s never to late to get around to it, but jump on your idea now before someone else does!

Need more inspiration for creating your unique new business online? Here are some other recent startups with innovative ideas:

Sqaure is a new online startup that allows people to take credit card payments using their mobile devices. Square is attempting to disrupt the credit card payment model by not only making it easy for anyone to accept credit card payments, but also by reducing the fees paid to credit card companies.

Hipmunk wants to be the best online flight and hotel search tool available by giving a graph-based listing of available flights with numerous ways to sort, including price, duration, and “agony”

Paper.li is an innovative online company that allows you to turn blog posts, facebook updates, twitter posts, and more into an online newspaper that you can share with other.

So what are you waiting for? Buy a domain name and get started on a website for your startup, and you could be the next billion dollar online company! While that scenario may be a little far-fetched, starting an online company that supplements your income or allows you to make a living entirely is actually pretty manageable with the right idea and enough effort.