working on a home automation using bluetooth network, any of you have worked on such application.

if any laready existing setup is avilable for the same, if you know any pls let me know.

I need some of the suggestion on this.

1. what will be the cost for this setup, using controlling 5 applianeces, with 100 mt range bluetooth dongle,
2. which is the best bluetooth dongle in the market,
3. what all the security constrints in this network.
4. what all the best sensors i can use?.
5. any other better alternative solution for the same home automation setup?.
6. you know any venders those who providing such service.

i have some of the solution for these issues, but i am looking for better solution.

Nice subject, and nice set of questions. Of course I could add mines : why do you want to start with blootooth ? I would expect, for security reasons, to do everthing as much wired as possible. In an ideal case study, a home automation should be not be based on a blootooth communication, because, in case of intrusion in your system, your house would start being crazy : the oven starting burning your meats, the shower wasting your water and the doors refusing your Mom's entering.
And of course, the real point is that this is not a tutorial, so it has no reason to be in the How-To's and Tutorials forum.
That's why I moved it here, in the hardware workshop.

It depends a bit on what on what you want to do, but sometimes it might be a better idea to use ZigBee instead of BT. You probably don't know wat ZB is, but it's a wireless protocol that is more targeted toward your application. The transferspeeds are much lower compared to BT, but it's way more responsive and it consumes a lot less energy (1-2 years on 2 AA batteries is expectable).

Returning to the BT story. Again, it depends a bit on what you want and how you want to do it. If you want to create the controllers yourself, then it probably won't cost about €15-20 per appliance (BT controllers are very cheap, only €5). A good USB dongle will probably set you back €20. You'll probably have to write the software yourself too.
If you want it all prefab, then it'll probably cost you a lot more.

I haven't find Home Automation Using Bluetooth but i have Home Automation using WiFI the components for that are
* Omni Pro II Home Automation Controller
* 1 Touch Screen
* 2 LCD Keypads
* 6-Zones of Audio
* 17 Automated Light Switches
* 20 Security Contacts
* 2 Thermostats
* Computer Control Software
* Complete Programming & Support
* 2 Wi Fi access point
Wi Fi Automation System