Recently i found new way to use your cellphone as fpv system. The whole concept moves around one application. It's good for rc cars, rc boats, rc hovercraft but not much useful for airborne models hovever you can use them for fpv demo. I am allready using this app from long time(not as fpv). The method i am posting here is for testing purpose only. It would be great if someone code such app for beta testing.
Check www[dot]livecast[dot]com
They have cellphone app runs on Android, Blackberry, Windows and Symbian OS.

Requirements
- HSPA handset with camera. Remove unnecessary weight of cellphone and cover it with foam, get second hand phone.
- 3G service provider

Advantage:
- It uses primary camera, which is good.
- Mobile to mobile and mobile to pc means whole world can see your fpv live.
- Record and stream video from low 24kbps to high 2mbps.
- You can mute sound to increase video quality.
- Public/ private stream option
- Runs on 2G but with delay

Disadvantage
- You can not completely rely on this fpv as it depends on signals
- Not good for high speed models.

Note
Before you go any further it is good to check TOS of your service provider and livecast.

I thought of using a mobile phone only as a video recorder, not as FPV. Yours is a good idea (and nice info), but I can't say it'll work satisfactorily unless it's a high-end smartphone, not just an ordinaru smart-phone.

I would say +1 to hyd_quads.. given the 3g speed and the cost implied in India presently.. the concept is brilliant, however it would be much more economical to use a wireless camera..

although wireless camera has a range and this mobile ..... run your brains... hehe the accessibility is extreme...

Yes Punty.. as you said, range is another parameter we need to consider...

why not just a simple idea....!!

take two 3G phones.... put one in the plane and one in your hand...... then start a video call.... take off....!!!

kinda virtually  unlimited range..and fast telecast also....!

Hey there friends thanks for comments.
@aerovishwa
It's same thing because finally it depends on signals and video call uses front camera, in most phone they come as 0.3 MP VGA camera. While this app can feed from primary camera.
@hyd_quad and punty
Guys you are right. Signals are issue but this app is useful for surface model. Me and my friends working on hovercraft project for university and they were asking me to put fpv system on it that can feed live video not recording. Now we can not afford it as finally we will have to submit project to university. Here BSNL 2G plan gives 25-30kBps speed for 98rs/month and at that speed this app works really well and feed live stream over the channel so not only one but all can see how it feels.
You can easily buy HSPA handset in 2nd hand price however we can directly feed live air shows events etc.

vid calls are possible with the back  cameras also....!!!

Got strike when i saw this topic.
http://www.rcgroups.com/forums/showthread.php?t=1623906

ya dharmik bhai!!!!
v can also use gps of smart phones...!!!
not only that v can also see the speed!!!
a motion detector is also posible!!!
also fpv+gps+gravity sensor!!!! a cheap samsung android 2.2 phone will b costing half of the system individually!!!

thank you karan bro.. +1

I sometimes use my tracks app for android to record my flights.
Here is one such flight of my Easy Glider.
https://maps.google.com/maps/ms?msa=0&msid=212981474886432651987.0004badeaebf25227361e

ps: check out my top speed. 126 Km/h >

Yeah not accurate as we expect. Btw what about gps accuracy of that test? because cellphones have A-GPS.

Why do you feel its not accurate

I know an aplication in playstore. Its name is web of cam internet. (There are two web of cam. one is internet other is wifi. The one with blue icon is wifi and one with green icon is 3g network). You need two smartphones and internet connectivity. First type your email id in The required box ( after downloading it to the two phones). Then click next, and Then there will be two buttons (one is viewer one is camera). Click viewer for the bigger phone, click camera for smaller phone. Then put camera optioned phone in the rc plane and look for a phone with an ip adress come in the viewer optioned phone. After  the ip adress come click in that then you have live streaming. You can also put flash light on or off also send sound like a walkie talkie also recieve sound and zoom. You can use it many ways. So try it now

Thanks !  I Will try it !