1060 Views 1 Reply Latest reply: May 6, 2010 7:37 AM by ChrisJ4203
Check the iPhone manual, page 50 http://manuals.info.apple.com/enUS/iPhone_UserGuide.pdf
From the Manual:
You can talk to more than one person at a time, and merge up to five calls, depending on your carrier.
Note: Conference calling may be an optional service in some countries. Contact your carrier for more information.
Create a conference call:
1 Make a call.
2 Tap Add Call and make another call. The first call is put on hold.
3 Tap Merge Calls. The calls are merged on one line and everyone can hear each other.
There is also a graph there that lets you know about adding and dropping more, but I'll let you read that yourself.
Hope that answers your question.