For text and picture sending try What's App
And for voice / video calls try Skype
We are at Old Key West now and wifi is not brilliant despite calling the I.T. people a few times to reboot the routers
I am going to be using MSN/Yahoo chat/Facebook messages and email. I have already told my friends and family not to text me or try to call as I've had voicemail temporarily deactivated and will be turning off data while roaming and turning off the network and riding only on wifi to avoid any charges (had a little accident failing to lock my keypad that cost me last year )
I really would only bother with skype if you are not using video as if wifi is slow, which it seems to be, it will be a frustrating exercise so the more basic your method of communication, the more reliable you are likely to find it