The Nexus One has the bigger screen at 3.7 inches. The iPhone 3GS had a 3.5 inch screen.
That really depends on what you want and value in a smartphone, since it is very subjective. However, the Samsung Nexus S is slower than an iPhone 4S but a bigger resolution, but in general, the iPhone 4S seems better.
The iPad's screen is 0.9 inches bigger.
The Nexus Series is a good Low-End Smartphone for its money. It seems, although they have a lot of manufacturing issues because of the way they were produced. To get more value for your money, The Newer, iPhone Series, is worth trying out.
Yes, as it is a smartphone.
IPhone
At the time of the phone's release, the Nexus 4 could be the iPhone 5's rival. However, with Android covering 80% of the smartphone market, and the Samsung Galaxy S3 having comparable specs and a much larger marketing push, you can argue that it's actually the S3 that may have been the "iPhone killer" of 2012.
iPhone, believe me.
The Iphone is better but the new nexus one it better than the Iphone
Not out of the box. The Nexus 5's screen lock settings include Slide, Face Unlock, Pattern, PIN, and Password. However, you can get a third party fingerprint scanner that does a similar function to the iPhone 5S.
The Galaxy Nexus has a clear advantage on display since it's a touchscreen smartphone (4.65 inch screen) vs. a smartphone with a physical keyboard (2.8 inch screen). Speaking of keyboards, it's personal opinion on which type of keyboard you would prefer (touchscreen vs. physical). The Galaxy Nexus is limited to only 16 or 32 GB of storage (no card slot), while the Blackberry has 8 GB of storage, but has a microSD card slot to expand storage up to 32 GB. The Galaxy Nexus has both a rear and front camera, while the Bold has only a rear camera.
iphone, nexus 1.
The 7 in Google Nexus 7 has not been openly mentioned to stand for anything. However, the recent Nexus tablet iterations (and to some degree, the phone as well) appear to refer to screen size. Both generations of the Nexus 7 have 7 inch and 7.02 inch screens respectively. The Nexus 10 has a 10.1 inch screen. The Nexus 4 has a 4.7 inch screen. The rumored Nexus 5 is supposed to have a 5 inch (or larger) screen.