Hands-On VRS (HOVRS) -- through AOL Instant Messenger (IM) video chat.
(Plus, check out this video about the HOVRS Mac-only widget.)

LifeLinks VRS -- through SightSpeed.

With both options, you have to add VRS interpreter "addresses" to your buddy list/phone book. The process for doing that in LifeLinks is more time consuming.
For non-Mac lovers, IM and SightSpeed do support some non-iSight web cams and are fully compatible on PCs.

As for my second question (about calling IP-based videophones like the VP-100 or i2eye with an iSight), I have not found a way to do it, but I am holding out hope that it's possible.

**
1. Are any Video Relay Services available to those with the Apple iSight?
2. Can the iSight be used to place a call to an IP-based videophone?

It retails for $480 here, but I found it for less (though not by much) on Froogle.
If it's stable and compatible with the VP-100/200, there just might be a market for it among residential video telephone consumers.

1. Are any Video Relay Services available to those with the Apple iSight?

& ???

2. Can the iSight be used to place a call to an IP-based videophone?

& ???

I will post the answers when I find out! First one to solve this mystery for me has my total respect, and maybe a prize.

Minimum frames per second required for understanding sign language or lipreading:

(The fourth image is a link to the NAD Videophone Numbering Web page.)

The ATIS VoIP subcommittee met July 13 to discuss ways to deploy a centralized videophone numbering network for VRS users. Sprint and Sorenson have contributed technical proposals to this subcommittee (similar to their numbering comments to the FCC), but mostly Sprint's proposal was discussed.

"Points noted" at the meeting:

The following oppositions have been filed in response to the request of Snap Telecommunications for a limited waiver of the [FCC's] Video Relay Service interoperability requirements.

CSDVRS
HOVRS
Sorenson VRS
Telecommunications for the Deaf

In response to this message, which is programmed to appear when VP-100 users dial non-Sorenson relay providers, Hands-On VRS filed this complaint with the FCC. It draws the following comparison:

"...Imagine if AT&T distributed a telephone to the public which intercepted calls destined for other long distance providers, stated that AT&T could not vouch for the quality of the telephone transmission, and asked if the caller still desired to make the call. The Commission would not stand for this. Yet, that is exactly what Sorenson is doing here..."

In response, Sorenson filed these comments.

As always, your comments are welcome.

VRS... Standards are part of the FCC's regs promulgated for TRS and are available at 47 C.F.R. § 64.601 - 64.605. The Minimum Standards are set forth at section 604. These regs are subject of course to FCC and court interpretation and supplementation through various orders ...

You can get copies of the regs (and any other federal regs) pretty easily at this website:

47 C.F.R. § 64.604 after the fold...