Gizmodo Has a great article on there site comparing the different Smartphone OSes. They give a quick description of each and some pictures as well. Read below and click the link to the full article.
You’re more likely than ever to buy a Smartphone, not just because they do so much more than dumb feature phones, with real email, decent web browsing and downloadable applications, but because they’re cheaper than ever. With the exception of some expensive ass unlocked-but-unsubsidized European models, you generally don’t have to pay more than $300 for a balls-to-the-wall Smartphone—though the voice plan plus data fees can easily run you $80 or more per month. Here’s a rudimentary overview of your choices (more now than ever before), why you might pick them, and why they might suck for you.
Giz Explains: Illustrated Guide to Smartphone OSes



