After several weeks of “secret” build-up, Google today publicly unveiled its new Nexus One mobile phone, which, of course, is built around Google’s Android phone software.

The new phone is considered an instant, strong competitor to Apple’s iPhone. The Nexus One features a removable battery, a five-megapixel camera with flash, and noise suppression.

Through the web store found at www.google.com/phone, consumers can buy the Nexus One without service (meaning any GSM network SIM card can be inserted into the device), or purchase the phone with service from one of Google’s operator partners. As new phones come to market through this channel, consumers will benefit from the ability to match a phone of their choice with the service plan that best meets their needs.

Nexus One is initially available from the Google web store in the United States without service for $529 or starting at $179 with a two-year contract from T-Mobile USA. In the near future, Verizon Wireless in the US and Vodafone in Europe plan to offer services to customers in their respective geographies.

Google’s press release is here.