A neat app for Android users
Install TiKL on ur Android (open http://market.android.com/search?q=TiKL in market) or iOS (itms://itunes.com/apps/TiklInc). Its FREE PTT.
Fast, simple and free - TiKL turns your phone into the ultimate Push To Talk (PTT) Walkie Talkie with instant messaging capability.
Available for FREE in Android Market and Apple AppStore.