(Most of the free ones have a bit of advertising in the beginning.)
It is a great service. It would be a great way to
test it as it's free. They do have add-ons for
reasonable rates.
Skype
the session. That's a GOOD THING because it's a
bandwidth hog when you have traffic from 5 people
coming in and out.You can also have a multi-user text chat and share
files and stuff.pretty good features and a
reasonable price.
If you need to call landlines using Skype
credit, the cost is still quite reasonable. You
can use Skype for calling to/from a number of
overseas locations with no problems. You can also
use it for conference calls with 4 or 5 people in
the US and suspect it would work decently for
overseas conference calling.
For calls between London, Buenos Aires, Germany,
USA and JP it Worked pretty well.
gotomeeting
gotomeeting is very good for hosting phone
conferences + Webinars.
Freeconferencecalls
it's only free for 4 months though. You can use
them for your training calls and seminars.
http://www.freeconferencecall.com/prodfreeconferencecall.asp
Also you can consider
intercall.AT&T etc.,Web Ex covers a number of these countries
(Australia, India, and China).
A good non-IP solution is budgetconferencing
minute call with three people only cost £10 which
seems pretty reasonable. If you need fewer than 20 participants and
don't need an operator, toll-free dial-in, or
dial-out services, then you can use their free
accudial.net service
Note:If you can't find one company that has all the
numbers you want, you can always buy a foreign
number and forward it to a US number (the cheapest
forward).
You can buy foreign numbers for your Asterisks
server from "didww.com" which has good quality
lines and very good forwarding capacity. I can get
numbers from many countries there.Costa Rica isn't listed and based on my knowledge
of VOIP is a country that generally protects it
phone company from foreign competition. In Dubai, this has stopped many of the web
conferencing companies from setting up shop. The
State simply demanded an outrageous fee for lines
which were being run out of the country. China,
India, Australia, are all easy. Costa Rica will be
your problem.