trutap - free mobile instant messaging, texting and social networking

trutap allows you to take your online social life where you go.
You can send group messages, SMS and email from your mobile phone for free.
You can also chat with your friends on IM (MSN, Yahoo!, AIM and ICQ ) and post to blogs, photo-sharing accounts and social networks - all from your mobile phone.
trutap is free to join and use.

fring - free mobile calls and IM

fring is a free mobile internet service & community that enables users to talk, chat & interact with other fringsters and their online communities, from their mobile phones.
You can use fring to communicate with all popular communities’ members - Skype, MSN Messenger, Google Talk, ICQ, SIP, Twitter, Yahoo!, AIM - without boundaries, and regardless of device, network operator, platform or the community to which they belong.
fring is totally free to download and free to use - the only cost incurred by the user is the mobile internet connection: 3G, EDGE, GPRS or Wi-Fi.
Here is a video showing how to make a free call using fring: