I'm frequently in the situation of needing to do a conference
telephone call with a small number of participants (<10).
I don't need operator assisted conferencing.
Typical duration is 1-2 hours.
Almost always, it is domestic U.S. participants only.

I'd prefer not enter into a long-term contract, but just pay
for individual conferences.

I've got verizon for my cell service, SBC for local, and MCI for
long distance. Their web sites are all awful. It appears, though
I'm not certain, that:

1. They all offer a high-end audio conferencing service.
This appears to be independent of whether I am a regular customer
or not, so I see no reason to choose these over anyone else's.

2. Some plans do include three-way calling, but that requires
a monthly fee to enable, and a telephone capable of it, and
is always limited to only 3 parties. [right?]

I'm often the only geek on these calls; I can't require webcams
and/or microphones of participants. Normal telephones must be supported.
Web conferencing and/or video chat might be of interest if it
includes normal pure telephone conferencing and is not significantly
more expensive, so that participants who are geeks can leverage the
other channels.

Phrase search of "conference calling" at google gets >100k entries,
and 8 sponsored links. There are a gazillion service providers.
A significant fraction are no doubt affiliate resellers, and/or
scammers.

I see prices all the way from 4.5cents/minute-person to
$1/minute-person, depending on whether there is a 800 number,
whether it is operator assisted, and other non-apparent factors.

Are there any decent reviews which contrast these different
services?
Who are the real market leaders, once all the affiliates are
eliminated?
What are competitive rates for what features, excluding
the unknown fly-by-night operations?
Am I right about the three-way calling limitations above?

Check out the website www.freeconference.com  I posted a question a
week ago to have someone research whether this company was legitimate
and alot more. The question was researched by a Google Answers
Researcher and is found under "Real Deal or Scam?
www.freeconference.com"  We used the freeconference service for the
first time this afternoon. We were very pleased with how easy it was
to setup the call. The quality was excellent. There was no fee for the
audio bridge from the company. Each participant merely paid their own
long-distance cost to connect to the bridge. This service will save us
a significant amount of money for our conference calling needs. I am
very pleased with this company and will recommend them very highly to
anyone looking for a great deal on conference calling.

A new website called www.conference-calls-review.com is aimed at
people in exactly your situation, who require a conference calling
service but have a hard time choosing from among the huge variety out
there.  The service allows users to rank and review conference call
service providers and to view them by ranking or popularity (sites
most visited).

Note that since the site is just starting out, it currently (7/2004)
holds a lengthy list of providers, but no reviews.  Any input you can
provide will be greatly appreciated.