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.
ANDROID by Google
The splashy new entrant into smartphone land, Android is Google's Linux-based open source mobile platform meant to bring real, constantly connected internet to phones. Even though it's debuting on a single phone, the G1 from HTC, expect to see the free OS show up on tons of phones, from HTC, Motorola, and others. It's totally modern and powerful, and the fact that it's open source makes it incredibly appealing to some developers, so most signs point to awesome applications and mobile internet.