Advice on VOIP for 1 man business

Hi,
I'm looking to put in a VOIP system to cut some costs and provide more flexibility. I'll explain what I'd like to do - I've been doing some research but find it all a bit daunting!

I'd like to keep my existing tel number as this is the one all of my clients call. I work either at home, in my offsite office or on the road. I'd like customers to call my existing number and for me to take it wherever I am.

Currently I use call forwarding on by BT line to divert to my mobile if I'm not in the office, which happens a lot! This works but is pretty pricey as I'm paying for a lot of mobile calls.

I'm not too sure what setup I'd need but was thinking about call forwarding to a VOIP number which I could pick up at home or in the office and if I'm out call forward to my mobile. I'm not too sure if this is the most elegant, effecient or cheapeast option!

Any help greatly appreciated. But I need reliability so would need a fallback on a landline if things went pear shapped.


Cheers Shaun.

trixbox.org has your free solution.
Running full VoIP here at home with Cisco IP phones.
Calls to me ring my extension, if I dont answer go to my cellphone, if I dont answer back to my home system's voicemail.
My voicemails are emailed to me as well via a wav file.
Quite slick actually.

I have a phone line at my house and a long distance VoIP service provider.
WHen I dial a long distance number the system via a dialing pattern I program knows which provider to use.

Also set my Cisco router to prioritize the voice traffic over the data so it never gets choppy, jittery, or any latency.

Cant tell I am using VoIP.