I've also set up an Asterisk server back at home and register to that to call various people I need to reach when I'm out and about.

On my end I'm not using anything fancy. I use SJPhone as a softphone client and a bluetooth headset to talk over.
That way I can set my laptop up on a table, like in my hotel room/office and go take the actual call across the room or in another room if I'm in an open office space and need privacy.