Good news to all eager waiting Google Wave fans. Google Wave is now open to everyone without anymore invitation. To begin, simply go to wave.google.com and start waving.

As per Google Wave Blog :

Starting today, we are making Google Wave openly available to everyone as part of Google Labs. You no longer need an invitation to wave — simply visit wave.google.com and sign right in. Likewise, if you are a Google Apps administrator at a business, school or organization, you can now easily enable Google Wave for all your users at no extra cost (more on ourEnterprise blog).

We began previewing Google Wave with individuals and a handful of Google Apps customerssix months ago. Since then, Wave has been used in a great many interesting ways. It’s clear from the invaluable feedback we’ve received that Wave is a great place to get work done, in particular for teams working together on projects that involve lots of discussion and close coordination.

Besides that, Google Wave is also launching several improvements to the Wave APIs and open sourcing additional components for developers building their own Wave services.