Using 2 Skype phones at the same time

Question

I recently purchased the RTX Dual phone 4088 which works like a dream.  We have several phone numbers through Skype and pay for the monthly plan for worldwide calls. 
My question is if I purchase a second RTX phone, can it be used at the same time as the other phone is being used?  We use the phone for business calls, mainly incoming, however, we are getting more and more calls and would like to have a second phone to be able to answer more calls at the same time.  Is this possible and if so, would it also work with 3 or 4 extra handsets?  All the calls are coming through on the same number so we don't really want to operate more than 1 account.
Any advice would be much appreciated before we purchase more handsets.

Answer 1

There's no proper way to do it - although forcing another instance of Skype as a different user seems to work... but test it thoroughly yourself before using with clients. Audio plays from both apps, not sure about mic. input. I'm not recommending it, and only tested briefly with Skype 6.3.59.602, but anyway...
For example - if you create another user account on the mac - named test, and after opening Skype as normal in your usual account, open Terminal & paste the following + enter
su test -c "/Applications/Skype.app/Contents/MacOS/Skype &"; exit
you should be asked for test's password in Terminal, then another Skype will open, although you'll likely get a warning message or two (choose cancel).