Google+ is a new social network from Google. It's still an exclusive party where you have to have an invite to join, and you can only get an invite from someone who is already a member. Is it worth the hype? Well right now it's like cookie dough that isn't finished baking, but there are still users ready to give up Facebook and make the switch. Use this guide to help you decide if it's worth it to beg your friends for an early Google+ invite, but you'll probably still want to wait a few months before you cancel your Facebook account.
You Are a Geek
If you are a nerd and you know it, Google+ is the place for you. Right now, Google+ is a geek's paradise. You can get direct access to feeds from your favorite nerds like Sergey Brin and Marissa Mayer from Google, the Tom Anderson from MySpace, Felicia Day, and even Mark Zuckerberg of Facebook (though he's yet to publicly post anything.) There's a lot of conversations and a lot of very nerdy jokes, much of which involves memes about Google+. There's even someone answering software development questions using Hangout, which is a multi-person video chat.
You Don't Trust Facebook
Facebook has angered a lot of users over privacy issues, malicious apps, and intrusive advertising. I spoke to one friend who told me he was cancelling his Facebook account and switching to Google+ for those reasons. He felt that Google was more straightforward with their advertising and more trustworthy with his personal info. Google has had its own critics over privacy issues, but Google+ has been largely praised for getting privacy right. Andy O'Donnell has a few addition tips for Google+ privacy settings.
You Use Other Google Services
Google+ is meant to dovetail with the rest of your Google experience, and that integration is only going to continue. If you're already using services like Gmail, Picasa, and Blogger, it makes sense to use a service that combines them all into one easy tag and share tool. Google+ members see a Google+ bar above many other Google services, allowing them to easily share the content they create.
You're Frustrated With Facebook and Twitter's Sharing Options
Google+ allows a combination of public and private posting options that make it easy to share with small or large groups. You're not stuck with either all public or all private posts. Google+ allows users to drag friends and contacts into Circles that define their relationship to you and allow for posts to smaller groups.
You Have Friends There
This is probably the most important aspect in a social network, and it's a bit of a catch-22. People don't tend to use social networks unless their friends are using them, and their friends aren't going to start unless you do. So, are your friends kicking the tires and making lots of posts? If not, you may just end up abandoning your page like countless others do with their Facebook pages and blogs. If you've got a strong community of friends already using the service, it's a great time to switch.
You Like Group Chat
I'll admit that video chat really isn't my thing, but if it's yours, and you've always been frustrated that you can only video chat one on one with most services, good news. You can chat with up to 10 people at a time using Hangouts. You can also group SMS chat using Huddles. I've heard a few grumbles that this is a feature in need of an audience, but I know plenty of people who text with their friends and have multiple SMS messages flying to different people all at once. Wouldn't it be easier to just have a group chat?
You Want to Help Make Google+ Better
Google+ isn't finished yet. It's limited release (as of July 2011) and still has the occasional glitch. For some that's a feature, not a bug. Google has been actively soliciting user feedback in the features you want to incorporate as the develop it. That means that if you're willing to put up with the growing pains, you can have some real formative input in how it grows. Just to warn you, "growing pains" can include things like 80 minutes of repeatedly getting the same email alert when the server fills up, notifications that stay stuck, or pictures that are supposed to be private ending up going out to your friends. If you want a mature product, wait until they open the service to everyone.
How to Get an Invite
Google+ is on the Web at plus.google.com You can get an invitation from someone who already has an account. The best way is to use your existing social networks, like Twitter or Facebook, and ask. This has the added bonus of making sure you've already got a friend.