If you are using for your ownself sure SKYPE is fine. But the other party I think also needs to use SKYPE.
If you are planning to do for for your company of maybe 30-50 people I'm afraid to say that it's not as simple as you think the financial outlay is huge as high as few hundred k
And the worse thing is you cannot use your existing network, you have to build a new seperate network, try to use your existing network and you will kill it

VOIP can use up all your company network bandwidth since voice is translated into packets. You have to buy new network routers, new switches then IP phones and all these going to cost a lot a lot of money.
My company actually thought of doing it but after we saw the quote for 300k+ worth of equipment, software and 10% every year after that as maintainence I think my management nearly fainted, they have since change their mind already. Good lah I have less to do.
