I love DimDim for webinars and instances when desktop sharing is needed, it works out nicely.
I personally use FreeConferenceCall.com (
http://www.freeconferencecall.com) for phone recording, teleseminars and interviews. When I don't do my podcast interviews via Skype, they are done using FreeConferenceCall.com. The VA Round Table episodes were recorded using FreeConferenceCall.com.
It supports up to 96 callers on one call and there is a 6 hour time limit per call. The one and only downside I have found (as Tammi mentioned already), is that you can only store one audio online at a time. So if you don't download your audio before doing another teleseminar recording, the old one is gone. By the way, the audio is provided in .wav format.
In doing some research in the past, below are some other conference call providers you may want to check out. I have used Free Conference Pro and while the admin panel was great and allowed for multiple recordings to be stored online; for me the quality of the call wasn't on par with FreeConferenceCall.com. However, that may have been the connection I had at the time too.
Free Conference Pro
http://www.freeconferencepro.com/
No Cost Conference Call
http://www.nocostconference.com/
Instant Conference Call
http://www.instantconference.com/fre...recording.aspx
Darlene