Google's senior director for mobile platforms Andy Rubin, has revealed that by the end of 2009 there will be at least 18 Android phones available worldwide.

(Samsung i7500, will be available soon)

According to Rubin, the final number of handsets could even go as high as 20, depending on how many devices use a more basic Android system without all the Google goodies.

The 18 to 20 Android handsets that will be made available over the course of the year will come from 8 or 9 different manufacturers, Rubin revealed.

It appears that carriers in the United States will be slower than in Europe in introducing new android phones this year. Rubin mentions that this is due to the high competition in the US and the need for carriers to develop their own distinctive user interfaces for the Android handsets.

There are currently three different ways in which manufacturers can include the android platform on their handsets. Whilst each Android flavor is ofcourse free, each option does place different requirements on the handset manufacturers and carriers.

1. The obligation-free option
device manufacturers can download a free version of Android, load onto their devices and provide access to as many or as few apps as they want. But the manufacturers cannot preload popular Google applications, like Gmail or Google calendar.

2. The small strings option
Same as Option 1, except that manufacturers sign a distribution agreement to include on the phone Google applications. Of the 18 to 20 phones coming out this year, Mr. Rubin said, 12 to 14 subscribe to this option.

3. The bigger strings option or the no-censorship version
These phones Google calls “The Google Experience.” They are physically distinguishable by the “Google” logo on the phone. They include a range of Google applications that the carrier and handset maker agree not to remove from the phone. The carrier and handset maker also agree not to censor access to the Android market. Meaning: if some developer comes up with an application that some people find distasteful, or that gets bad press, it must nevertheless remain available to consumers. Of the phones coming out this year, 5 to 6 belong to this category, Mr. Rubin said.