I have seen this same answer a few times, create new AppleID's for everyone... But I know there is another way.
I have one AppleID I share with two phones and both my kids iPod touch's, and a couple of iPad's (6 drives total, one ID)
They all have iMessage and all share my single AppleID for purchases, iCloud and everything else. (This is perfect for Find my iPhone as well)
All I did was authorize another email address for each, and then use that in iMessage. This lets me contact each separately and by their own email address, this also works for FaceTime.
You can authorize the new email address inside the FaceTime/iMessage app on that device. The only issue is you have to have access to that email account to answer the authorization email, but that only took a couple of seconds.
They don't need their own AppleID's
This only took me a few minutes to setup.
The cool part is now my 7 year old can text my wife and I on our phones from home, no extra cost at all.
Scott
That also means anyone who knows your password can then get your iMessages. Also if they restore the phone themselves, they will get it by default. I know you can remove it later, but it's not a good solution IMO.
It's really simple..setup each phone with a new id.
Create a new gmail address
Goto appleid.apple.com and change email address to the new one
Dissociate the other address from it
Stup store with new credentials.
The other issue is if everyone has the email address you used for your appleid, and you don't set that up as a valid secondary, nobody will find you unless they all add the new me.com address you added. Gmail users may not have to setup anything...gmail will alias anything with a plus to your account...
So you may be able to (depending on apple) change your I'd to
myemail+apple@gmail.com - this is a useful gmail feature, it allows you to avoid getting on spam lists if you add it to each site you sign up for...
Just some thoughts.
Ps I confirmed this works. You can change the mail address to
youremail+apple@gmail.com and therefore retain your main email account easily.