One of my prior major pain points was that I didn't have a conference calling solution for clients or client groups.
I was trying to find a cost effective solution that didn't have a bunch of add-ons that I didn't need, or pay hundreds or thousands of dollars a year for a service I may only use once or twice a quarter. Most of my calls are one-on-one, or to a husband-wife couple that call me from one line and have the phone on speaker. I stumbled upon OpenVoice, which is owned by LogMeIn, the same company that owns GoToMeeting.
I have to say I'm pleasantly surprised. Audio quality seems acceptable with no delay, and the organizer has an online dashboard with several options available such as mute a specific user, mute all, record the call, lock the call, kick someone from the call, etc.
This company provides local call-in numbers for many different countries. Some are toll but most are toll free.
Best part, there is no monthly fee. Instead, the fee structure is based on time used at $0.08 per user per minute.
Not trying to push anything, and I get nothing for this, just thought I'd post it in case someone is looking for a similar solution. I really had to dig to find this company. Note this is audio only, no video or screen sharing.