In the world of smartphones, it’s either iOS or Android (News - Alert); Windows Phone is for a smaller crowd and the Blackberry user base is dwarfed by all of the above.

iOS runs on only one device – the iPhone. Windows Phone (News - Alert) offers a few options, but Android by far offers the widest selection of handsets.

Staircase 3 did a little bit of research based on the nearly 700,000 users who have used its OpenSignalMaps service, concluding that there are close to 4,000 devices with the app installed. Findings also showed Samsung’s (News - Alert) Galaxy S II is hands down the most popular handset on the market right now.

Thousands of devices to choose from at first sounds like a great accomplishment for Google (News - Alert) and its mobile OS – and equally as convenient for the picky smartphone user who has to find the perfect gadget. But thinking in terms of support and staying up to date on the software end, it could very well be downright inconvenient for the user.

To put things into perspective, there is basically one three-member family of devices with official support from Google – the Nexus handsets – including the Nexus One, Nexus S and Galaxy Nexus.

These devices are always the first to get full system upgrades, and none of them ship with the dreaded junkware users are plagued with when making a purchase from service providers. Nexus skips the middleman and is deployed directly from OEMs and Google. 

It certainly wouldn’t be a light task for providers, OEMs and/or Google to keep all 4,000 devices current – especially with those of lower, entry-level quality.

Why are there so many more devices sporting Android than any other mobile OS? For one, it’s open source – free to modify and redistribute. Any company who wants to roll out a few Android devices can effortlessly do so as they see fit, with minimal costs at that.

Business Insider noted that Microsoft (News - Alert) limits manufacturers to strict guidelines regarding the Windows Phone platform, ensuring that no third-party bloatware or UI tweaks like HTC’s Sense for Android makes it to the devices.

Google has been working on getting its mobile OS a little bit regulated lately, with plans to make the Nexus family more widely available through setting up contracts with a range of manufacturers.