Some times I can text from my ipad2 and other times I can'tiPhoneiPhone
SOmetimes it lets me text and other times it says that they do not haveiMessage and they are using iphone
iPad 2, iOS 4
The other person has to have iMessage activated, and has not blocked messages from you.
Using FaceTime http://support.apple.com/kb/ht4319
Troubleshooting FaceTime http://support.apple.com/kb/TS3367
The Complete Guide to FaceTime + iMessage: Setup, Use, and Troubleshooting
Troubleshooting FaceTime and iMessage activation
http://support.apple.com/kb/TS4268
Using FaceTime and iMessage behind a firewall
http://support.apple.com/kb/HT4245
iOS: About Messages
http://support.apple.com/kb/HT3529
Set up iMessage
http://www.apple.com/ca/ios/messages/
Troubleshooting Messages
http://support.apple.com/kb/TS2755
Setting Up Multiple iOS Devices for iMessage and Facetime
http://macmost.com/setting-up-multiple-ios-devices-for-messages-and-facetime.htm l
FaceTime and iMessage not accepting Apple ID password
Unable to use FaceTime and iMessage with my apple ID
https://discussions.apple.com/thread/4649373?tstart=90
For non-Apple devices, check out the TextFree app https://itunes.apple.com/us/app/text-free-textfree-sms-real/id399355755?mt=8
Cheers, Tom 😉