For those who were not present at the meetup, kontalk is a Free Software replacement for whatsapp - you can chat with anyone if you know their phone number using a data connection (cheaper sms for many people). See http://kontalk.org
Currently it is available only on android. Their next version would support XMPP and it would make it easy to get it working on other platforms.
Karan asked me how they would know if my contact has a kontalk account if they don't store everyone's number? I asked the upstream and he confirmed my guess.
When you register your number, the server sends you an sms to confirm your number and the number is discarded. A one way hash of the number is used as username (like storing passwords, the server can never guess the number based on the hash). So when you want to talk to someone in your phone contact list, the client will make a hash and send it to the server to find the public. The public key of the user will be signed by the server and all communications will be end to end encrypted. Only way to spy would installing apps on the users' phones.
This is simply brilliant, the encryption solution we have been waiting for, as easy as whatsapp!
Cheers Praveen
2014/1/18, Rigved Rakshit r.phate@gmail.com:
Hello,
There might be connectivity issue at the venue. It is advisable to have a backup Internet connection handy.
Best Regards, Rigved -- http://mm.ilug-bom.org.in/mailman/listinfo/linuxers