VOIP Widgets for Web 2.0 communication

For quite sometime , i was looking at different tools that are available for users in social networking to communicate( voice communication). Here is a list of companies that provide a way to communicate between users,group and visitors. Though there are other companies( sitophone,skype,vePhone etc) that provide voip service, but don't fit in as a widget.

Jaxtr
Jaxtr is a perfect click to call kind of widget for social networking. It has a pretty slick interface.
This widget can be used to send
Text Message
Send Voicemail messages to users or receive voice messages from visitors of the website
Engage in a voice Call without revealing your original phone number. Perfect feature for any online dating or community interaction
This is a free service. You buy jax credits to forward calls to your phone. 100 free credits per month. You can send unlimited calls to voice mail for free and unlimited text messages for free. Calls to other Jaxtr users are also free

Jangl
I think jangl needs to do more work on the widget side. I guess adding jangl call me widget to different social networking might not be fun.
Not sure what would be their billing/pricing model. Still in beta and a free service
When you register, you get a JANGL ID associated with that is a phone number assigned by jangl. This becomes your identity. Not quite like grandcentral single number approach. User can call you by dialing this number assigned by jangl. I liked the idea of translating the email id to a phone number. Complete privacy assured when communicating on the net.
The four companies that have partnered with Jangl are Various, Inc., Justin.tv, Fubar and Revision3. Various, Inc. is the parent company of FriendFinder, and has 20+ online communities around the world
Registration is free.

gizmocall
Web based soft phone developed using adobe flash technology. Could be used as call me widgets in most of the social networking. Their web sites doesn’t have more information on how to add the call me widgets in most of the social networking communicates. I feel they need to focus more on helping the average Joe install gizmo client in different social networking communities.
Gizmocall is integrated with live journal.(Using this service, users can call mobile numbers, initiate conference calls and send instant messages using their LiveJournal account information)
For registered users, Initial 5 minutes call is free.

yackpack
Allows private groups to send voice message to each other. It’s more like an offline voice message communication. It’s Worthy of note that it’s founded by Stanford team.
Interesting demo from yackpack team.
Yackpack Demo
This is a free service

wengovisio
Flash based audio and video widget. It supports presence feature that lets users know when a user is online or offline. None of the other widgets support this feature. Quite simple widget for someone more interested in interacting with the visitors and getting in touch. Based on the availability (offline), visitors can leave a voice message. However, it doesn’t support interface with a PSTN/Mobile network. Users need to install this widget for real time communication. Iam sure wengo must be working to support offline text messaging and interface to other network.
This is a free service. It’s a subsidiary of 9 Telecom, France’s second largest telecom.

busta
I would say busta is similar to gizmo call except that it works only on internet explorer (they use activex control which is not supported on other browsers). In order to use this feature, user needs to install an activex control that is of a very small size(less than 100k).
It’s a paid service. The first 10 seconds of the call is free. WOW what a great deal :-)

jajah
Jajah is a simple web interface for voip calling. Initially they ventured into the market as a low cost VOIP company. I really admire them for their business acumen. They have partnered with many companies to provide VOIP service; Great strategy. From a technology standpoint, I don’t think they invented rocket science. However, these guys are unbelievable when it comes to marketing their simple product into mainstream. This is what separates them from ordinary folks. Personally I admire them.
Jajah has partnered with eHarmony to provide voice communication for all eHarmony
users.
Registration is free, you get USD 0.63 for the first time when u register

jaduka
Though doesn’t fit into a complete voice widget for social networking. I still think their product can be used for online communication with users or visitors of blogs/website. Click and connect, users need to register for click to connect and configure a phone number where u they can be reached. Once registered, jaduka gives three options that can be used for online communication--
Call popup window
Website call button
Email call button
Offers 60 free minutes, need to recharge the account based on the pricing for different countries.

I feel most of these companies have similar products, but are being packaged different for wide array of market segments. Since most of them are in beta, not sure what’s going to be their business model from revenue generation standpoint.